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  1. Agricultural Development, Land Change, and Livelihoods in Tanzania's Kilombero Valley

    NASA Astrophysics Data System (ADS)

    Connors, John Patrick

    The Kilombero Valley lies at the intersection of a network of protected areas that cross Tanzania. The wetlands and woodlands of the Valley, as well as the forest of surrounding mountains are abundant in biodiversity and are considered to be critical areas for conservation. This area, however, is also the home to more than a half million people, primarily poor smallholder farmers. In an effort to support the livelihoods and food security of these farmers and the larger Tanzanian population, the country has recently targeted a series of programs to increase agricultural production in the Kilombero Valley and elsewhere in the country. Bridging concepts and methods from land change science, political ecology, and sustainable livelihoods, I present an integrated assessment of the linkages between development and conservation efforts in the Kilombero Valley and the implications for food security. This dissertation uses three empirical studies to understand the process of development in the Kilombero Valley and to link the priorities and perceptions of conservation and development efforts to the material outcomes in food security and land change. The first paper of this dissertation examines the changes in land use in the Kilombero Valley between 1997 and 2014 following the privatization of agriculture and the expansion of Tanzania's Kilimo Kwanza program. Remote sensing analysis reveals a two-fold increase in agricultural area during this short time, largely at the expense of forest. Protected areas in some parts of the Valley appear to be deterring deforestation, but rapid agricultural growth, particularly surrounding a commercial rice plantation, has led to loss of extant forest and sustained habitat fragmentation. The second paper focuses examines livelihood strategies in the Valley and claims regarding the role of agrobiodiversity in food security. The results of household survey reveal no difference or lower food security among households that diversify their

  2. Over-diagnosis of malaria by microscopy in the Kilombero Valley, Southern Tanzania: an evaluation of the utility and cost-effectiveness of rapid diagnostic tests

    PubMed Central

    2013-01-01

    Background Early and accurate diagnosis of febrile patients is essential to treat uncomplicated malaria cases properly, prevent severe malaria, and avert unnecessary anti-malarial treatments. Improper use of anti-malarials increases the risk of adverse drug reaction and the evolution of drug/parasite resistance. While microscopy is the most common form of malaria diagnosis, concerns over its accuracy have prompted the incorporation of malaria rapid diagnostic tests (RDTs) into many national malaria control programmes. Methods Over a three-month period, a direct comparison between microscopy and RDTs was made in a rural, private dispensary in the Kilombero Valley, Morogoro District, southern Tanzania, with the aim of estimating the extent of malaria over-diagnosis and over-treatment with anti-malarials. The study cohort was made up of patients referred by the dispensary’s clinician for malaria testing. One hundred percent of patients approached agreed to participate in this study and were then tested using both microscopy and RDTs. Using the results from the comparison of the two tests at this dispensary, the potential cost effectiveness of introducing RDTs to a neighbouring public health centre was estimated on the basis of this centre’s past malaria records spanning December 2007 to August 2011. Results At the private dispensary, the apparent prevalence of malaria was 78% based on microscopy whereas the true prevalence, calculated using RDTs as the gold standard, was estimated at 14%. This discrepancy indicates that when using microscopy as the sole diagnostic test, malaria is being over-diagnosed by approximately a factor of five in this setting. At the public clinic, apparent malaria prevalence based on microscopy was 74%. If similar rates of over-diagnosis are assumed, 5,285 patients of the 6,769 patients positively diagnosed with malaria using microscopy were likely given unnecessary anti-malarials, and their true cause of illness was not addressed. The

  3. Capturing and explaining preference heterogeneity for wetland management options in the Kilombero Valley, Tanzania.

    PubMed

    Speelman, Stijn; Mombo, Felister; Vandermeulen, Valerie; Phillip, Damas; Van Huylenbroeck, Guido

    2015-01-01

    Wetland degradation has recently received considerable research attention. Although wetlands are valuable ecosystems, their actual value is difficult to measure because the services they provide often do not have market values. The current study seeks to investigate the preferences for wetland management options in the Kilombero Valley, central Tanzania using choice modeling. The results show that both respondents from the Kilombero Valley and Morogoro Municipality desire improvements in the condition of the wetlands. This indicates that the ongoing degradation is not socially optimal. A second finding is that the preferences for wetland conservation are heterogeneous and can be linked to livelihood characteristics. Communities living in the area, for example, are highly dependent on the wetland for their livelihood and would be impacted by conservation measures. Therefore, in order to reduce the pressure on wetlands, it is necessary and imperative to explore the options for alternative income-generating activities or to focus, for example, on technologies to improve efficiency and effectiveness in crop production.

  4. Capturing and Explaining Preference Heterogeneity for Wetland Management Options in the Kilombero Valley, Tanzania

    NASA Astrophysics Data System (ADS)

    Speelman, Stijn; Mombo, Felister; Vandermeulen, Valerie; Phillip, Damas; Van Huylenbroeck, Guido

    2015-01-01

    Wetland degradation has recently received considerable research attention. Although wetlands are valuable ecosystems, their actual value is difficult to measure because the services they provide often do not have market values. The current study seeks to investigate the preferences for wetland management options in the Kilombero Valley, central Tanzania using choice modeling. The results show that both respondents from the Kilombero Valley and Morogoro Municipality desire improvements in the condition of the wetlands. This indicates that the ongoing degradation is not socially optimal. A second finding is that the preferences for wetland conservation are heterogeneous and can be linked to livelihood characteristics. Communities living in the area, for example, are highly dependent on the wetland for their livelihood and would be impacted by conservation measures. Therefore, in order to reduce the pressure on wetlands, it is necessary and imperative to explore the options for alternative income-generating activities or to focus, for example, on technologies to improve efficiency and effectiveness in crop production.

  5. Factors determining the choice of hunting and trading bushmeat in the Kilombero Valley, Tanzania.

    PubMed

    Nielsen, Martin Reinhardt; Jacobsen, Jette Bredahl; Thorsen, Bo Jellesmark

    2014-04-01

    Regulation of illegal bushmeat trade is a major conservation challenge in Africa. We investigated what factors are most likely to induce actors in the bushmeat trade to shift to an alternative occupation by conducting a choice experiment with 325 actors in the bushmeat trade in the Kilombero Valley, Tanzania. Specifically, we asked respondents to choose between hunting or trading bushmeat and alternative salary-paying work, in a set of hypothetical scenarios where the attributes of these alternatives were varied and included measures of command and control, price of substitute meat, daily salary in the work option, and whether or not cows were donated to the respondent. We modeled the choice contingent on socioeconomic characteristics. The magnitude of fines and patrolling frequency had a significant but very low negative effect on the probability of choosing to engage in hunting or trading bushmeat compared with the salary of an alternative occupation. Donation of livestock and the price of substitute meats in the local market both affected the choice significantly in a negative and a positive direction, respectively. The wealthier a household was the more likely the respondent was to choose to continue hunting or trading bushmeat. On the margin, our results suggest that given current conditions in the Kilombero Valley on any given day 90% of the respondents would choose salary work at US$3.37/day over their activities in the bushmeat trade, all else equal.

  6. Knowledge, attitudes and practices on Rift Valley fever among agro pastoral communities in Kongwa and Kilombero districts, Tanzania.

    PubMed

    Shabani, Sasita S; Ezekiel, Mangi J; Mohamed, Mohamed; Moshiro, Candida S

    2015-08-21

    Rift valley fever (RVF) is a re-emerging viral vector-borne disease with rapid global socio-economic impact. A large RVF outbreak occurred in Tanzania in 2007 and affected more than half of the regions with high (47 %) case fatality rate. Little is known about RVF and its dynamics. A cross sectional study was conducted to assess the knowledge, attitudes and practices regarding RVF in Kongwa and Kilombero districts, Tanzania. We conducted a cross sectional survey among a randomly selected sample of individuals in 2011. We administered questionnaires to collect data on demographic characteristics, knowledge on symptoms, mode of transmission, prevention, attitudes and health seeking practices. A total of 463 community members participated in this study. The mean (±SD) age was 39.8 ± 14.4 years and 238 (51.4 %) were female. Majority of respondents had heard of RVF. However, only 8.8 % knew that mosquitoes were transmitting vectors. Male respondents were more likely to have greater knowledge about RVF. A small proportion mentioned clinical signs and symptoms of RVF in animals while 73.7 % mentioned unhealthy practices related to handling and consumption of dead animals. Thorough boiling of milk and cooking of meat were commonly mentioned as preventive measures for RVF. Majority (74.6 %) sought care for febrile illness at health facilities. Few (24.3 %) reported the use of protective gears to handle dead/sick animal while 15.5 % were consuming dead animals. Our study highlights the need to address the limited knowledge about RVF and promoting appropriate and timely health seeking practices. Rift valley fever outbreaks can be effectively managed with collaborative efforts of lay and professional communities with a shared perception that it poses a serious threat to public and animal health. The fact that this study was conducted in "high risk transmission areas" warrants further inquiry in other geographic regions with relatively low risk of RVF.

  7. Antenatal care in practice: an exploratory study in antenatal care clinics in the Kilombero Valley, south-eastern Tanzania.

    PubMed

    Gross, Karin; Armstrong Schellenberg, Joanna; Kessy, Flora; Pfeiffer, Constanze; Obrist, Brigit

    2011-05-20

    The potential of antenatal care for reducing maternal morbidity and improving newborn survival and health is widely acknowledged. Yet there are worrying gaps in knowledge of the quality of antenatal care provided in Tanzania. In particular, determinants of health workers' performance have not yet been fully understood. This paper uses ethnographic methods to document health workers' antenatal care practices with reference to the national Focused Antenatal Care guidelines and identifies factors influencing health workers' performance. Potential implications for improving antenatal care provision in Tanzania are discussed. Combining different qualitative techniques, we studied health workers' antenatal care practices in four public antenatal care clinics in the Kilombero Valley, south-eastern Tanzania. A total of 36 antenatal care consultations were observed and compared with the Focused Antenatal Care guidelines. Participant observation, informal discussions and in-depth interviews with the staff helped to identify and explain health workers' practices and contextual factors influencing antenatal care provision. The delivery of antenatal care services to pregnant women at the selected antenatal care clinics varied widely. Some services that are recommended by the Focused Antenatal Care guidelines were given to all women while other services were not delivered at all. Factors influencing health workers' practices were poor implementation of the Focused Antenatal Care guidelines, lack of trained staff and absenteeism, supply shortages and use of working tools that are not consistent with the Focused Antenatal Care guidelines. Health workers react to difficult working conditions by developing informal practices as coping strategies or "street-level bureaucracy". Efforts to improve antenatal care should address shortages of trained staff through expanding training opportunities, including health worker cadres with little pre-service training. Attention should be paid to

  8. Development of a hydrogeological conceptual wetland model in the data-scarce north-eastern region of Kilombero Valley, Tanzania

    NASA Astrophysics Data System (ADS)

    Burghof, Sonja; Gabiri, Geofrey; Stumpp, Christine; Chesnaux, Romain; Reichert, Barbara

    2017-08-01

    Understanding groundwater/surface-water interactions in wetlands is crucial because wetlands provide not only a high potential for agricultural production, but also sensitive and valuable ecosystems. This is especially true for the Kilombero floodplain wetland in Tanzania, which represents a data-scarce region in terms of hydrological and hydrogeological data. A comprehensive approach combining hydrogeological with tracer-based assessments was conducted, in order to develop a conceptual hydrogeological wetland model of the area around the city of Ifakara in the north-eastern region of Kilombero catchment. Within the study site, a heterogeneous porous aquifer, with a range of hydraulic conductivities, is underlain by a fractured-rock aquifer. Groundwater chemistry is mainly influenced by silicate weathering and depends on groundwater residence times related to the hydraulic conductivities of the porous aquifer. Groundwater flows from the hillside to the river during most of the year. While floodwater close to the river is mainly derived from overbank flow of the river, floodwater at a greater distance from the river mainly originates from precipitation and groundwater discharge. Evaporation effects in floodwater increase with increasing distance from the river. In general, the contribution of flood and stream water to groundwater recharge is negligible. In terms of an intensification of agricultural activities in the wetland, several conclusions can be drawn from the conceptual model. Results of this study are valuable as a base for further research related to groundwater/surface-water interactions and the conceptual model can be used in the future to set up numerical flow and transport models.

  9. Advancing understanding in the face of data limitations and difficult conditions: Estimating storage contributions to streamflow in Tanzania's rapidly developing Kilombero Valley

    NASA Astrophysics Data System (ADS)

    Lyon, S. W.; Koutsouris, A. J.

    2016-12-01

    Robust natural variability and experimental design may help to overcome the data limitations and difficult conditions that typify much of the global south. This, in turn, can facilitate the application of advanced techniques to help inform management with science (which is sorely needed for guiding development). As an example on this concept, we used a limited amount of weekly water chemistry as well as stable water isotope data to perform end-member mixing analysis in a glue frame work (G-EMMA) in one main catchment and two sub-catchments of Kilombero Valley, Tanzania. How water interacts across the various storages in this region, which has been targeted for rapid agricultural intensification and expansion, is still largely unknown making estimation of potential impacts (not to mention sustainability) associated with various development scenarios difficult. Our results showed that there were, as would be expected, considerable uncertainties related to the characterization of end-members in this remote system. Regardless, some robust estimates could be made on contributions to seasonal streamflow variability. For example, it appears that there is a low connectivity between the deep groundwater and the stream system throughout the year. Also, there is a considerable wetting up period required before overland flow occurs. We demonstrate that the apparent miss-match between state-of-the-science techniques and data limitations (not to mention the issues associated with difficult working environments) can be bridged by leveraging experimental design and natural system variability. This is promising as we seek to advance our science in more and more remote (and in particular developing) regions to allow for important improvements for management of less and less available resources. Thus, in spite of large uncertainties this work highlights how research may still provide an improved system understanding of hydrological flows even when working under less than perfect

  10. Rift Valley fever outbreak, southern Mauritania, 2012.

    PubMed

    Sow, Abdourahmane; Faye, Ousmane; Ba, Yamar; Ba, Hampathé; Diallo, Diawo; Faye, Oumar; Loucoubar, Cheikh; Boushab, Mohamed; Barry, Yahya; Diallo, Mawlouth; Sall, Amadou Alpha

    2014-02-01

    After a period of heavy rainfall, an outbreak of Rift Valley fever occurred in southern Mauritania during September-November 2012. A total of 41 human cases were confirmed, including 13 deaths, and 12 Rift Valley fever virus strains were isolated. Moudjeria and Temchecket Departments were the most affected areas.

  11. Rift Valley Fever Outbreak, Southern Mauritania, 2012

    PubMed Central

    Sow, Abdourahmane; Faye, Ousmane; Ba, Yamar; Ba, Hampathé; Diallo, Diawo; Faye, Oumar; Loucoubar, Cheikh; Boushab, Mohamed; Barry, Yahya; Diallo, Mawlouth

    2014-01-01

    After a period of heavy rainfall, an outbreak of Rift Valley fever occurred in southern Mauritania during September–November 2012. A total of 41 human cases were confirmed, including 13 deaths, and 12 Rift Valley fever virus strains were isolated. Moudjeria and Temchecket Departments were the most affected areas. PMID:24447334

  12. Hydrothermal system in Southern Grass Valley, Pershing County, Nevada

    SciTech Connect

    Welch, A.H.; Sorey, M.L.; Olmsted, F.H.

    1981-01-01

    Southern Grass Valley is a fairly typical extensional basin in the Basin and Range province. Leach Hot Springs, in the southern part of the valley, represents the discharge end of an active hydrothermal flow system with an estimated deep aquifer temperature of 163 to 176/sup 0/C. Results of geologic, hydrologic, geophysical and geochemical investigations are discussed in an attempt to construct an internally consistent model of the system.

  13. The hydrothermal system in southern Grass Valley, Pershing County, Nevada

    USGS Publications Warehouse

    Welch, Alan H.; Sorey, M.L.; Olmsted, F.H.

    1981-01-01

    Southern Grass Valley is typical extensional basin in the Basin and Range province. Leach Hot Springs, in the southern part of the valley, represents the discharge end of an active hydrothermal flow system with an estimated deep aquifer temperature of 163-173C. This report discusses results of geologic, hydrologic, geophysical and geochemical investigations used in an attempt to construct an internally consistent model of the system. (USGS)

  14. Magnetotelluric Data, Southern San Luis Valley, Colorado

    USGS Publications Warehouse

    Williams, Jackie M.; Rodriguez, Brian D.

    2007-01-01

    Introduction The population of the San Luis Valley region is growing rapidly. The shallow unconfined and the deeper confined Santa Fe Group aquifer in the San Luis Basin is the main sources of municipal water for the region. Water shortfalls could have serious consequences. Future growth and land management in the region depend on accurate assessment and protection of the region's ground-water resources. An important issue in managing the ground-water resources is a better understanding of the hydrogeology of the Santa Fe Group and the nature of the sedimentary deposits that fill the Rio Grande rift, which contain the principal ground-water aquifers. The U.S. Geological Survey (USGS) is conducting a series of multidisciplinary studies of the San Luis Basin located in southern Colorado. Detailed geologic mapping, high-resolution airborne magnetic surveys, gravity surveys, an electromagnetic survey, called magnetotellurics (MT), and hydrologic and lithologic data are being used to better understand the aquifer systems. The primary goal of the MT survey is to map changes in electrical resistivity with depth that are related to differences in rock type. These various rock types help control the properties of aquifers in the region. This report does not include any interpretation of the data. Its purpose is to release the MT data acquired at the 22 stations shown in figure 1.

  15. Surface Deformation in Imperial Valley, Southern California

    NASA Astrophysics Data System (ADS)

    Eneva, M.; Adams, D.; Falorni, G.; Morgan, J.

    2013-12-01

    The Imperial Valley in southern California is subjected to significant tectonic deformation resulting from the relative movement of the North American and Pacific plates. It is characterized by large earthquakes, frequent swarm activity, and aseismic events. High heat flow makes possible the operation of geothermal fields, some of which cause man-made surface displacements superimposed on the tectonic deformation. We apply radar interferometry (InSAR) to analyze Envisat ASAR data for the period 2003-2010. The SqueeSAR technique is used to obtain deformation time series and annual rates at numerous locations of permanent and distributed scatterers (PS and DS). SqueeSAR works very well in agricultural areas, where conventional differential InSAR (DinSAR) fails. We observe differential movements marking the Superstition Hills, San Andreas, and Imperial faults. The Imperial fault traverses agricultural fields, where DInSAR does not work and thus our SqueeSAR observations are the first for this fault (Fig. 1). We also observe steps in the deformation time series around the Superstition Hills fault from an October 2006 aseismic event and the April 2010 M7.2 earthquake south of the U.S.-Mexico border. Significant annual deformation rates are detected in the current geothermal fields. For example, subsidence of up to -50 mm/year is seen at the Salton Sea field (Fig. 2), and both subsidence and uplift are seen at Heber. We also determine the deformation baseline at prospective geothermal fields, thus making it possible in the future to distinguish between man-made and tectonic causes of surface deformation. Fig. 1. Line-of-sight (LOS) deformation indicates differential displacement on both sides of Imperial Fault. Movements away from the satellite are shown in yellow to red, and towards the satellite in blue. Larger deformation is associated with two geothermal fields, Heber (to the south-west) and East Mesa (to the east). Fig. 2. Subsidence in the Salton Sea geothermal

  16. Is It Working? Lysimeter Monitoring in the Southern Willamette Valley Groundwater Management Area

    EPA Science Inventory

    Groundwater nitrate contamination affects thousands of households in the southern Willamette Valley and many more across the Pacific Northwest. The southern Willamette Valley Groundwater Management Area (SWV GWMA) was established in 2004 due to nitrate levels in the groundwater ...

  17. Is It Working? Lysimeter Monitoring in the Southern Willamette Valley Groundwater Management Area

    EPA Science Inventory

    Groundwater nitrate contamination affects thousands of households in the southern Willamette Valley and many more across the Pacific Northwest. The southern Willamette Valley Groundwater Management Area (SWV GWMA) was established in 2004 due to nitrate levels in the groundwater ...

  18. 40 CFR 81.81 - Merrimack Valley-Southern New Hampshire Interstate Air Quality Control Region.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 18 2013-07-01 2013-07-01 false Merrimack Valley-Southern New... Designation of Air Quality Control Regions § 81.81 Merrimack Valley-Southern New Hampshire Interstate Air Quality Control Region. The Merrimack Valley Southern New Hampshire Interstate Air Quality Control Region...

  19. 40 CFR 81.81 - Merrimack Valley-Southern New Hampshire Interstate Air Quality Control Region.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 18 2012-07-01 2012-07-01 false Merrimack Valley-Southern New... Designation of Air Quality Control Regions § 81.81 Merrimack Valley-Southern New Hampshire Interstate Air Quality Control Region. The Merrimack Valley Southern New Hampshire Interstate Air Quality Control Region...

  20. 40 CFR 81.81 - Merrimack Valley-Southern New Hampshire Interstate Air Quality Control Region.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 18 2014-07-01 2014-07-01 false Merrimack Valley-Southern New... Designation of Air Quality Control Regions § 81.81 Merrimack Valley-Southern New Hampshire Interstate Air Quality Control Region. The Merrimack Valley Southern New Hampshire Interstate Air Quality Control Region...

  1. 40 CFR 81.81 - Merrimack Valley-Southern New Hampshire Interstate Air Quality Control Region.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 17 2010-07-01 2010-07-01 false Merrimack Valley-Southern New... Designation of Air Quality Control Regions § 81.81 Merrimack Valley-Southern New Hampshire Interstate Air Quality Control Region. The Merrimack Valley Southern New Hampshire Interstate Air Quality Control Region...

  2. Model Program: Southern Lehigh High School, Center Valley, PA

    ERIC Educational Resources Information Center

    Colelli, Richard

    2009-01-01

    In this article, the author describes the technology education program at Southern Lehigh High School, Center Valley, Pennsylvania. The school district is presently providing an educational program known for its excellence and forward-looking perspective, which is sensitive to the changing needs of its students. Within the technology education…

  3. Model Program: Southern Lehigh High School, Center Valley, PA

    ERIC Educational Resources Information Center

    Colelli, Richard

    2009-01-01

    In this article, the author describes the technology education program at Southern Lehigh High School, Center Valley, Pennsylvania. The school district is presently providing an educational program known for its excellence and forward-looking perspective, which is sensitive to the changing needs of its students. Within the technology education…

  4. Ground-water conditions in southern Utah Valley and Goshen Valley, Utah

    USGS Publications Warehouse

    Cordova, R.M.

    1970-01-01

    The investigation of ground-water conditions in southern Utah Valley and Goshen Valley, Utah, was made by the U. S. Geological Survey as part of a cooperative program with the Utah Department of Natural Resources, Division of Water Rights, to investigate the water resources of the State. The purposes of the investigation were to (1) determine the occurrence, recharge, discharge, movement, storage, chemical quality, and availability of ground water; (2) appraise the effects of increased withdrawal of water from wells; and (3) evaluate the effect of the Central Utah Project on the ground-water reservoir and the water supply of Utah Lake.This report presents a description of the aquifer system in the two valleys, a detailed description of the ground-water resources, and conclusions about potential development and its effect on the hydrologic conditions in the valleys. Two supplementary reports are products of the investigation. A basic-data release (Cordova, 1969) contains most of the basic data collected for the investigation, including well characteristics, drillers' logs, water levels, pumpage from wells, chemical analyses of ground and surface waters, and discharge of selected springs, drains, and streams. An interpretive report (Cordova and Mower, 1967) contains the results of a large-scale aquifer test in southern Utah Valley.

  5. Groundwater quality in the Southern Sacramento Valley, California

    USGS Publications Warehouse

    Bennett, George L.; Fram, Miranda S.; Belitz, Kenneth

    2011-01-01

    Groundwater provides more than 40 percent of California's drinking water. To protect this vital resource, the State of California created the Groundwater Ambient Monitoring and Assessment (GAMA) Program. The Priority Basin Project of the GAMA Program provides a comprehensive assessment of the State's groundwater quality and increases public access to groundwater-quality information. The Southern Sacramento Valley is one of the study units being evaluated.

  6. 77 FR 47921 - Pecos Valley Permian Railroad, L.L.C. d/b/a Pecos Valley Southern Railway Company-Lease Exemption...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-08-10

    ... Surface Transportation Board Pecos Valley Permian Railroad, L.L.C. d/b/a Pecos Valley Southern Railway Company--Lease Exemption--Pecos Valley Southern Railway Company Pecos Valley Permian Railroad, L.L.C. d/b... operate 24 miles of rail line located between milepost 0.0 at Pecos, Tex., and milepost 24.0, north of...

  7. Hydrologic Evaluation of the Jungo Area, Southern Desert Valley, Nevada

    USGS Publications Warehouse

    Lopes, Thomas J.

    2010-01-01

    RecologyTM, the primary San Francisco waste-disposal entity, is proposing to develop a Class 1 landfill near Jungo, Nevada. The proposal calls for the landfill to receive by rail about 20,000 tons of waste per week for up to 50 years. On September 22, 2009, the Interior Appropriation (S.A. 2494) was amended to require the U.S. Geological Survey to evaluate the proposed Jungo landfill site for: (1) potential water-quality impacts on nearby surface-water resources, including Rye Patch Reservoir and the Humboldt River; (2) potential impacts on municipal water resources of Winnemucca, Nevada; (3) locations and altitudes of aquifers; (4) how long it will take waste seepage from the site to contaminate local aquifers; and (5) the direction and distance that contaminated groundwater would travel at 95 and 190 years. This evaluation was based on review of existing data and information. Desert Valley is tributary to the Black Rock Desert via the Quinn River in northern Desert Valley. The Humboldt River and Rye Patch Reservoir would not be affected by surface releases from the proposed Jungo landfill site because they are in the Humboldt basin. Winnemucca, on the Humboldt River, is 30 miles east of the Jungo landfill site and in the Humboldt basin. Groundwater-flow directions indicate that subsurface flow near the proposed Jungo landfill site is toward the south-southwest. Therefore, municipal water resources of Winnemucca would not be affected by surface or subsurface releases from the proposed Jungo landfill site. Basin-fill aquifers underlie the 680-square-mile valley floor in Desert Valley. Altitudes around the proposed Jungo landfill site range from 4,162 to 4,175 feet. Depth to groundwater is fairly shallow in southern Desert Valley and is about 60 feet below land surface at the proposed Jungo landfill site. A groundwater divide exists about 7 miles north of the proposed Jungo landfill site. Groundwater north of the divide flows north towards the Quinn River. South of

  8. Is it working? A look at the changing nutrient practices in the Southern Willamette Valley's Groundwater Management Area

    EPA Science Inventory

    Groundwater nitrate contamination affects thousands of households in the southern Willamette Valley and many more across the Pacific Northwest. The southern Willamette Valley Groundwater Management Area (SWV GWMA) was established in 2004 due to nitrate levels in the groundwater ...

  9. Is it working? A look at the changing nutrient practices in the Southern Willamette Valley's Groundwater Management Area

    EPA Science Inventory

    Groundwater nitrate contamination affects thousands of households in the southern Willamette Valley and many more across the Pacific Northwest. The southern Willamette Valley Groundwater Management Area (SWV GWMA) was established in 2004 due to nitrate levels in the groundwater ...

  10. An Isotopic view of water and nitrogen transport through the vadose zone in Oregon's southern Willamette Valley's Groundwater Management Area

    EPA Science Inventory

    Background/Question/MethodsGroundwater nitrate contamination affects thousands of households in Oregon's southern Willamette Valley and many more across the Pacific Northwest. The southern Willamette Valley Groundwater Management Area (SWV GWMA) was established in 2004 due to nit...

  11. Paleoseismology of the Southern Section of the Black Mountains and Southern Death Valley Fault Zones, Death Valley, United States

    USGS Publications Warehouse

    Sohn, Marsha S.; Knott, Jeffrey R.; Mahan, Shannon

    2014-01-01

    The Death Valley Fault System (DVFS) is part of the southern Walker Lane–eastern California shear zone. The normal Black Mountains Fault Zone (BMFZ) and the right-lateral Southern Death Valley Fault Zone (SDVFZ) are two components of the DVFS. Estimates of late Pleistocene-Holocene slip rates and recurrence intervals for these two fault zones are uncertain owing to poor relative age control. The BMFZ southernmost section (Section 1W) steps basinward and preserves multiple scarps in the Quaternary alluvial fans. We present optically stimulated luminescence (OSL) dates ranging from 27 to 4 ka of fluvial and eolian sand lenses interbedded with alluvial-fan deposits offset by the BMFZ. By cross-cutting relations, we infer that there were three separate ground-rupturing earthquakes on BMFZ Section 1W with vertical displacement between 5.5 m and 2.75 m. The slip-rate estimate is ∼0.2 to 1.8 mm/yr, with an earthquake recurrence interval of 4,500 to 2,000 years. Slip-per-event measurements indicate Mw 7.0 to 7.2 earthquakes. The 27–4-ka OSL-dated alluvial fans also overlie the putative Cinder Hill tephra layer. Cinder Hill is offset ∼213 m by SDVFZ, which yields a tentative slip rate of 1 to 8 mm/yr for the SDVFZ.

  12. Analysis of gravity data in Central Valleys, Oaxaca, southern, Mexico

    NASA Astrophysics Data System (ADS)

    Gonzalez, T.; Ferrusquia, I.

    2015-12-01

    The region known as Central Valleys is located in the state of Oaxaca, southern, Mexico (16.3o- 17.7 o N Lat. and 96 o - 97 o W Long.) In its central portion is settled the capital of the state. There are very few published detailed geological studies.. Geomorphological and geological features, indicates that Central Valleys and surrounding mountains conform a graben structure. Its shape is an inverted Y, centred on Oaxaca City. The study area was covered by a detailed gravity survey with a homogenous distribution of stations. The Bouguer gravity map is dominated by a large gravity low, oriented NW-SE. In order to know the characteristics of anomalies observed gravity, data transformations were used. The use of spectral methods has increased in recent years, especially for the estimation of the depth of the source. Analysis of the gravity data sheds light on the regional depth of the Graben basement and the spatial distribution of the volcanic rocks

  13. Morphological properties of tunnel valleys beneath the southern sector of the former Laurentide Ice Sheet

    NASA Astrophysics Data System (ADS)

    Livingstone, Stephen; Clark, Chris

    2016-04-01

    Tunnel valleys have been widely reported on the bed of former ice sheets and are considered an important expression of subglacial meltwater drainage. Although known to have been cut by erosive meltwater flow, the water source and development of channels has been widely debated. Possible mechanisms include: (i) gradual formation by water flow in a subglacially deforming bed into channels under steady-state conditions; (ii) time-transgressive formation close to the ice margin by drainage of supraglacial meltwater to the bed or of meltwater temporarily impounded behind a permafrost wedge; and or (iii) by catastrophic subglacial meltwater floods. We have mapped and analysed the spatial pattern and morphometry of tunnel valleys and associated glacial bedforms along the southern sector of the former Laurentide Ice Sheet from high-resolution digital elevation models. Around 2000 tunnel valleys have been mapped, revealing a well-organised pattern of sub-parallel, semi-regularly spaced valleys that cluster together in distinctive networks. The tunnel valleys are typically <20 km long, and 0.5-3 km wide and preferentially terminate at moraines. They tend to be associated with outwash fans, eskers, glacial curvilineations, giant current ripples, and hill-hole-pairs. A relative age of the tunnel valleys, based on cross-cutting relationships, is used to resolve when individual tunnel valleys and networks were eroded. Our results suggest a time-transgressive origin for most tunnel valleys (i.e. they grow upstream) with some contributions from large meltwater drainage events.

  14. MX Siting Investigation. Gravity Survey - Southern White River Valley, Nevada.

    DTIC Science & Technology

    1980-05-22

    included gravity surveys in ten valleys in Arizona (five), Nevada (two), New Mexico (two), and California (one). The gravity data were obtained for...Verification Sites, Nevada-Utah Siting Region, FN-TR-36. , 1980, Active Faults and Eartquake Hazards in the FY 79 Verification sites, Nevada-Utah Siting

  15. Geophysical Investigations of Structures within Southern Fish Lake Valley, California

    NASA Astrophysics Data System (ADS)

    McBride, K.; Ferguson, J. F.; Oldow, J. S.

    2015-12-01

    The 80km Fish Lake Valley Fault Zone makes up the northern portion of the Furnace Creek - Death Valley Fault Zone, a 250km right lateral oblique strike slip system that accounts for up to 25% of the relative motion between the Pacific and North American Plates. The Cucomongo Canyon Restraining bend lies to the south of Fish Lake Valley, and causes localized uplift. The developmental history of the Cucomongo Canyon restraining bend and the resultant uplift, deformation, and displacement is the focus of an integrated study by the Miles Geoscience Center at the University of Texas at Dallas. This specific part of the study focuses on the southernmost section of Fish Lake Valley, where Paleozoic sedimentary rocks are juxtaposed with Cenozoic sediments on multiple faulted boundaries. Structural constraints are not very well known as the faults are locally obscured by Quaternary alluvial deposits of various ages. Analysis of high resolution topography, produced from LiDAR scanning performed by the Miles team, and imagery shows subtle geomorphic expressions related to faulting. A near surface geophysical survey utilizing high resolution seismic refraction and microGal gravity measurements was done to explore the subsurface beneath the alluvium. Forward models were created to identify faults and ascertain vertical offsets and orientations. The geophysical models indicate a zone of extensional deformation north of the restraining bend

  16. Provenance, Offset Equivalent and Palinspastic Reconstruction of the Miocene Cajon Valley Formation, Southern California

    NASA Astrophysics Data System (ADS)

    Stang, Dallon Michael

    Petrographic, conglomerate and detrital-zircon analyses of formations in southern California can determine consanguineous petrofacies and lithofacies that help constrain paleotectonic and paleogeographic reconstructions of the southwestern United States. Arkosic sandstone of the lower Middle Miocene Cajon Valley formation is exposed on the southwest edge of the Mojave block and juxtaposed against Mesozoic and Paleozoic rocks by the San Andreas fault (SAf). Early work in Cajon Valley referred to the formation as Punchbowl, due to its similar appearance to the Punchbowl Formation at Devil's Punchbowl (northwest along the SAf). However, paleontological work placed Cajon Valley strata in the Hemingfordian-Barstovian (18-14 Ma), as opposed to the Clarendonian-Hemphillian (13-9 Ma) Punchbowl Formation. Since the Cajon Valley formation was deposited prior to being truncated by the San Andreas fault, the 2400m-thick, laterally extensive subaerial deposits likely were deposited across what is now the fault trace. Restoring 310 km of dextral slip on the SAf system should indicate the location of offset equivalent sandstone. Restoration of slip on the SAf system places Cajon Valley adjacent to the Caliente and La Panza Ranges, east of San Luis Obispo. Although analysis of detrital zircon from Cenozoic sandstone throughout southern California has been crucial in establishing paleodrainage areas, detrital zircon from the Cajon Valley and equivalent formations had not been analyzed prior to this study. Paleocurrents measured throughout the Cajon Valley formation indicate a source to the NE, in the Mojave Desert. Sandstone samples analyzed in thin section using the Gazzi-Dickinson method of point-counting are homogeneously arkosic, with slight compositional variability, making differentiation of the Cajon Valley formation and potential offset equivalents problematic. However, Branch Canyon Sandstone and Santa Margarita Formation samples are compositionally the best match for the

  17. Miocene rapakivi granites in the southern Death Valley region, California, USA

    USGS Publications Warehouse

    Calzia, James P.; Ramo, O.T.

    2005-01-01

    Rapakivi granites in the southern Death Valley region, California, include the 12.4-Ma granite of Kingston Peak, the ca. 10.6-Ma Little Chief stock, and the 9.8-Ma Shoshone pluton. All of these granitic rocks are texturally zoned from a porphyritic rim facies, characterized by rapakivi textures and miarolitic cavities, to an equigranular aplite core. These granites crystallized from anhydrous and peraluminous to metaluminous magmas that were more oxidized and less alkalic than type rapakivi granites from southern Finland. Chemical and isotope (Nd–Sr–Pb) data suggest that rapakivi granites of the southern Death Valley region were derived by partial melting of lower crustal rocks (possibly including Mesozoic plutonic component) with some mantle input as well; they were emplaced at shallow crustal levels (4 km) in an actively extending orogen.

  18. Miocene rapakivi granites in the southern Death Valley region, California, USA

    USGS Publications Warehouse

    Calzia, J.P.; Ramo, O.T.

    2005-01-01

    Rapakivi granites in the southern Death Valley region, California, include the 12.4-Ma granite of Kingston Peak, the ca. 10.6-Ma Little Chief stock, and the 9.8-Ma Shoshone pluton. All of these granitic rocks are texturally zoned from a porphyritic rim facies, characterized by rapakivi textures and miarolitic cavities, to an equigranular aplite core. These granites crystallized from anhydrous and peraluminous to metaluminous magmas that were more oxidized and less alkalic than type rapakivi granites from southern Finland. Chemical and isotope (Nd-Sr-Pb) data suggest that rapakivi granites of the southern Death Valley region were derived by partial melting of lower crustal rocks (possibly including Mesozoic plutonic component) with some mantle input as well; they were emplaced at shallow crustal levels (4 km) in an actively extending orogen.

  19. Selected hydrologic data for southern Utah and Goshen Valleys, Utah, 1890-1992

    USGS Publications Warehouse

    Stolp, B.J.; Drumiler, M.J.; Brooks, L.E.

    1993-01-01

    This report contains hydrologic data collected in southern Utah and Goshen Valleys from 1890 to 1992. Southern Utah and Goshen Valleys are south of Salt Lake City in Utah County, north-central Utah. The area is bounded on the east and south by the Wasarch Range, on the south by Long Ridge, on the west by the East Tintic Mountains and the Mosida Hills, and on the north by a line through about the middle of T. 7 S. Southern Utah Valley and Goshen Valley are divided by the northern tip of Long Ridge, West Mountain, and Utah Lake. The area is in the Basin and Range physiographic province and includes about 390 square miles. Hydrologic data presented include records of over 400 wells. drillers' logs for selected wells, water-level data from wells, well discharge, and chemical analyses of water from about 90 wells. Discharge, water temperature, and specific conductance of water are given for about 15 selected springs and drains, and for streams and canals.

  20. Magnetotelluric sounding data, stations 1 to 22, Southern San Luis Valley, Colorado, 2006

    USGS Publications Warehouse

    Rodriguez, Brian D.

    2016-01-01

    This dataset includes the locations of magnetotelluric (MT) stations collected in 2006 in the Southern San Luis Valley, Colorado. The U.S. Geological Survey conducted a series of multidisciplinary studies, including MT surveys, in the San Luis Valley to improve understanding of the hydrogeology of the Santa Fe Group and the nature of the sedimentary deposits comprising the principal groundwater aquifers of the Rio Grande rift. The shallow unconfined and the deeper confined Santa Fe Group aquifers in the San Luis Basin are the main sources of municipal water for the region. The population of the San Luis Valley region is growing rapidly and water shortfalls could have serious consequences. Future growth and land management in the region depend on accurate assessment and protection of the region's groundwater resources.

  1. Interpretation of magnetic surveys in intermontane valleys of Nevada and southern New Mexico

    USGS Publications Warehouse

    Bath, G.D.

    1976-01-01

    An evaluation of the magnetic method of geophysical exploration in intermontane valleys is made through examples of magnetic properties, magnetic surveys, reduction of data, and analysis of magnetic anomalies from some valley areas. Measurements of magnetic properties of samples collected along valley margins or from drill holes indicate that the anomaly-producing rocks are mostly Tertiary volcanic flows in Nevada and mostly Cretaceous-Tertiary intrusives in southern New Mexico. Aeromagnetic data were compiled as both observed and residual anomalies from surveys at various flight-line spacings and intervals from ground surface. Theoretical anomalies from known models were analyzed to recover data on depth, width, and magnetization of models and thereby establish reliability of methods used by certain investigators. These methods were then applied to measured anomalies to obtain information about the igneous rock structures that are buried beneath nonmagnetic valley alluvium. Recommendations made for future valley studies include aeromagnetic surveys flown 150 m above ground surface and at 800 m spacing; measurement of magnetic properties from outcrop samples, drill-core samples, and magnetometer logging of uncased drill holes; and use of the interpretation from gravity surveys in the same area.

  2. Principal facts for gravity stations in the Elko, Steptoe Valley, Coyote Spring Valley, and Sheep Range areas, eastern and southern Nevada

    USGS Publications Warehouse

    Berger, D.L.; Schaefer, D.H.; Frick, E.A.

    1990-01-01

    Principal facts for 537 gravity stations in the carbonate-rock province of eastern and southern Nevada are tabulated and presented. The gravity data were collected in support of groundwater studies in several valleys. The study areas include the Elko area, northern Steptoe Valley, Coyote Spring Valley, and the western Sheep Range area. The data for each site include values for latitude, longitude, altitude, observed gravity, free- air anomaly, terrain correction, and Bouguer anomaly (calculated at a bedrock density of 2.67 g/cu cm. (USGS)

  3. Shallow velocity structure in the Imperial Valley region of Southern California

    NASA Astrophysics Data System (ADS)

    Ma, Y.; Stock, J. M.; Hole, J. A.; Fuis, G. S.

    2013-12-01

    The Imperial Valley, located south of the Salton Sea of Southern California, contains a pull-apart basin formed by the on-going oblique extension between the southernmost San Andreas fault and the northern Imperial fault. In this very seismically active area, the earthquakes tend to occur in the form of seismic swarms (e.g. events in August 2012), often related to the geothermal systems in the valley. Previous active seismic studies (e.g. Fuis et al. 1979, Parsons and McCarthy 1996) have revealed major crustal structures including the shallow basin structures in the valley and surroundings, based primarily on 2D models. A better 3D structure model is still awaiting construction to provide improved information on the location of earthquakes, faults, fault-zone properties, and the evolution of the basin. The 2011 Salton Seismic Imaging Project (SSIP) deployed a seismic array at 2-km grid spacing in the central northern part of the valley (Line 11), and three longer seismic lines across the valley with active sources (Lines 1, 2, and 3). Here we will present the shallow (to 8-km depth) 3D structure in this region obtained by modeling the traveltimes of the first arrivals in these recordings and from earlier experiments. We have processed arrivals from all shots at all receivers, from the SSIP dataset, in the region south of the Salton Sea. Relevant data from the 1979 Imperial Valley experiment has also been used. The 3D structure of the valley was inverted from the surface to 8-km depth using the technique of Hole (1992). On average, the velocity increases rapidly from ~2 km/s at the surface to 5.6 km/s at 5 km depth, a velocity range corresponding to the unmetamorphosed sediments (Fuis et al. 1984). Below 5-km depth, velocity increases slowly to 6.3 km/s at 8-km depth, a velocity range corresponding to the metasedimentary rocks, or 'basement' (Fuis et al. 1984). In depth slices, geothermal areas are characterized by high velocity zones. Specifically, we observe a

  4. Death Valley bright spot: a midcrustal magma body in the southern Great Basin, California

    SciTech Connect

    de Voogd, B.; Serpa, L.; Brown, L.; Hauser, E.; Kaufman, S.; Oliver, J.; Troxel, B.W.; Willemin, J.; Wright, L.A.

    1986-01-01

    A previously unrecognized midcrustal magma body may have been detected by COCORP deep seismic reflection profiles in the Death Valley region of the southern Great Basin. High-amplitude, relatively broad-band reflections at 6 s (15 km) are attributed to partially molten material within a subhorizontal intrusion. This bright spot extends laterally at least 15 km beneath central Death Valley. A moderately dipping normal fault can be traced from the inferred magma chamber upward to a 690,000-yr-old basaltic cinder cone. The fault zone is inferred to have been a magma conduit during the formation of the cinder cone. Vertical variations in crustal reflection character suggest that the Death Valley magma body may have been emplaced along a zone of decoupling that separates a faulted brittle upper crust from a more ductile and/or intruded lower crust. The Death Valley bright spot is similar to reflections recorded by COCORP in 1977 in the Rio Grande rift, where both geophysical and geodetic evidence support the inference of a tabular magma chamber at 20-km depth.

  5. Benthic macrofauna communities of the submersed Pleistocene Elbe valley in the southern North Sea

    NASA Astrophysics Data System (ADS)

    Rehm, Peter; Rachor, Eike

    2007-06-01

    Macrozoobenthic community structure was studied in two surveys along a transect of 13 stations following the submersed Pleistocene Elbe valley in the south-eastern North Sea during May to June 2000 and March 2001. Two replicates of bottom samples were taken with a van Veen grab of 0.1 m2 sampling size. In order to analyse the benthic macrofauna communities, the animals obtained were identified and counted, and MDS and cluster analysis were performed. Out of 200 taxa identified, 84 were polychaetes, 46 molluscs, 40 crustaceans, 15 echinoderms, and 15 belonged to other groups. Mean abundance was 4,860 individuals per m2, mean biomass 32.9 g ash free dry mass per m2. Mean diversity was 1.76 and mean evenness 0.54. The macrofauna of the Pleistocene Elbe valley is composed of three associations according to the cluster analysis. Each association is described by a combination of characterizing and discriminating species. An Amphiura-brachiata― Tellimya-ferruginosa-association was found in the south-eastern part of the depression, whereas a transitional association with elements of both assemblages lead to an Amphiura- filiformis― Galathowenia- oculata― Nuculoma- tenuis-association in the north-western part of the valley. In the context of the entire southern North Sea, both associations are small-scale substructures, and as such are contained in the Nucula- nitidosa-community and the Amphiura- filiformis-community, respectively. A north-westward shift of the community of the southern Elbe valley was found and discussed as a possible consequence of warm winters of the last decades.

  6. Chemical and Isotopical Patterns of Nitrate Contamination in the Southern Willamette Valley, Oregon

    NASA Astrophysics Data System (ADS)

    Vick, C. F.; Selker, J.

    2004-12-01

    A persistent problem with elevated NO3 concentrations in rural drinking wells in the southern Willamette Valley, Oregon has been documented since the 1930's. We explore the origin of this contaminant. The objective of this study was to use isotopes of NO3 and other ionic chemical indicators to determine the sources of NO3 in drinking water wells in the southern Willamette Valley, OR. Many non-point sources were found to contribute to the elevated levels of NO3 in ground water, including high-density residential and high-intensity agricultural. 466 wells met the criteria to be included in the study: (1) less than 75 feet in depth (2) installed after 1960 (3) domestic use and (4) be located in the southern Willamette Valley. 120 wells were sampled during the summer of 2003. Geologic units, dominant land use and soil types were determined for each well in an attempt to determine vulnerability of wells for NO3 contamination. 20 drinking water wells were selected to undergo isotopic and further chemical analyses. In order to determine the chemical and isotopic fingerprints of the dominant sources of NO3 contamination soil samples were augered from 10 septic drain fields and water samples were collected below 10 agricultural fields. NO3-N concentrations in the study area ranged from below detection (<0.20 mg/L) to 13.70 mg/L, with a mean concentration of 4.81 mg/L. There was a statistically significant trend (i.e. P < 0.05) in NO3-N with well depth, well age, pH and SO4. Findings suggest that geologic setting is an important factor in predicting vulnerability, with land use also being important but less so. Determination of septic and agricultural sources of NO3 contamination were inconclusive, though various chemical indicators were found to suggest the origin of the NO3.

  7. Produced water chemistry data for samples from four petroleum wells, Southern San Joaquin Valley, California, 2014

    USGS Publications Warehouse

    Davis, Tracy A.; Kulongoski, Justin; McMahon, Peter B.

    2016-01-01

    The U.S. Geological Survey (USGS) in cooperation with the California State Water Resources Control Board collected produced water samples from four petroleum wells in the southern San Joaquin Valley on November 5, 2014. This digital dataset contains the site information, analyzing laboratories and methods, and water chemistry and quality control results for these samples. Water chemistry results include concentrations of dissolved hydrocarbon gases and their isotopic composition; concentrations of inorganic constituents including salinity, major ions, and nutrients; dissolved organic carbon; and stable isotopes of water and strontium dissolved in water. Samples were analyzed by 5 laboratories operated or contracted by the USGS.

  8. Biologically relevant physical measurements in the ice-free valleys of southern Victoria Land: soil temperature profiles and ultraviolet radiation.

    PubMed

    Nienow, J A; Meyer, M A

    1986-01-01

    As part of the ongoing comprehensive study of the cryptoendolithic microbial community in the ice-free valleys of southern Victoria Land, thermal properties of the soil and the ultraviolet radiation regime were measured. Although soil temperature profiles have been measured in the ice-free valleys (e.g., Cameron et al. 1970; Cameron 1972), these are the first such data from higher elevations. This is apparently the first time the ultraviolet radiation regime has been measured in the Antarctic.

  9. Biologically relevant physical measurements in the ice-free valleys of southern Victoria Land: soil temperature profiles and ultraviolet radiation

    NASA Technical Reports Server (NTRS)

    Nienow, J. A.; Meyer, M. A.; Friedmann, E. I. (Principal Investigator)

    1986-01-01

    As part of the ongoing comprehensive study of the cryptoendolithic microbial community in the ice-free valleys of southern Victoria Land, thermal properties of the soil and the ultraviolet radiation regime were measured. Although soil temperature profiles have been measured in the ice-free valleys (e.g., Cameron et al. 1970; Cameron 1972), these are the first such data from higher elevations. This is apparently the first time the ultraviolet radiation regime has been measured in the Antarctic.

  10. Biologically relevant physical measurements in the ice-free valleys of southern Victoria Land: soil temperature profiles and ultraviolet radiation

    NASA Technical Reports Server (NTRS)

    Nienow, J. A.; Meyer, M. A.; Friedmann, E. I. (Principal Investigator)

    1986-01-01

    As part of the ongoing comprehensive study of the cryptoendolithic microbial community in the ice-free valleys of southern Victoria Land, thermal properties of the soil and the ultraviolet radiation regime were measured. Although soil temperature profiles have been measured in the ice-free valleys (e.g., Cameron et al. 1970; Cameron 1972), these are the first such data from higher elevations. This is apparently the first time the ultraviolet radiation regime has been measured in the Antarctic.

  11. Impact of valley fills on streamside salamanders in southern West Virginia

    USGS Publications Warehouse

    Wood, Petra Bohall; Williams, Jennifer M.

    2013-01-01

    Valley fills associated with mountaintop-removal mining bury stream headwaters and affect water quality and ecological function of reaches below fills. We quantified relative abundance of streamside salamanders in southern West Virginia during 2002 in three streams below valley fills (VFS) and in three reference streams (RS). We surveyed 36 10- × 2-m stream transects, once in summer and fall, paired by order and structure. Of 2,343 salamanders captured, 66.7% were from RS. Total salamanders (adults plus larvae) were more abundant in RS than VFS for first-order and second-order reaches. Adult salamanders had greater abundance in first-order reaches of RS than VFS. Larval salamanders were more abundant in second-order reaches of RS than VFS. No stream width or mesohabitat variables differed between VFS and RS. Only two cover variables differed. Silt cover, greater in VFS than RS first-order reaches, is a likely contributor to reduced abundance of salamanders in VFS. Second-order RS had more boulder cover than second-order VFS, which may have contributed to the higher total and larval salamander abundance in RS. Water chemistry assessments of our VFS and RS reported elevated levels of metal and ion concentrations in VFS, which can depress macroinvertebrate populations and likely affect salamander abundance. Valley fills appear to have significant negative effects on stream salamander abundance due to alterations in habitat structure, water quality and chemistry, and macroinvertebrate communities in streams below fills.

  12. On the formation of the tunnel valleys of the southern Laurentide ice sheet

    USGS Publications Warehouse

    Hooke, R. LeB; Jennings, C.E.

    2006-01-01

    Catastrophic releases of meltwater, produced by basal melting and stored for decades in subglacial reservoirs at high pressure, may have been responsible for eroding the broad, deep tunnel valleys that are common along the margins of some lobes of the southern Laurentide ice sheet. We surmise that these releases began when the high water pressure was transmitted to the margin through the substrate. The water pressure in the substrate at the margin would then have been significantly above the overburden pressure, leading to sapping failure. Headward erosion of a conduit in the substrate (piping) could then tap the stored water, resulting in the outburst. In some situations, development of a siphon may have lowered the reservoir below its overflow level, thus tapping additional water. Following the flood, the seal could have reformed and the reservoir refilled, setting up conditions for another outburst. Order of magnitude calculations suggest that once emptied, a subglacial reservoir could refill in a matter of decades. The amount of water released during several outbursts appears to be sufficient to erode a tunnel valley. We think that tunnel valleys are most likely to have formed in this way where and when the glacier margin was frozen to the bed and permafrost extended from the glacier forefield several kilometers back under the glacier, as reservoirs would then have been larger and more common, and the seal more robust and more likely to reform after an outburst. ?? 2006 Elsevier Ltd. All rights reserved.

  13. Modelling groundwater over-extraction in the southern Jordan Valley with scarce data

    NASA Astrophysics Data System (ADS)

    Alfaro, Paulina; Liesch, Tanja; Goldscheider, Nico

    2017-01-01

    To deal with the challenge of groundwater over-extraction in arid and semi-arid environments, it is necessary to establish management strategies based on the knowledge of hydrogeological conditions, which can be difficult in places where hydrogeological data are dispersed, scarce or present potential misinformation. Groundwater levels in the southern Jordan Valley (Jordan) have decreased drastically in the last three decades, caused by over-extraction of groundwater for irrigation purposes. This study presents a local, two-dimensional and transient numerical groundwater model, using MODFLOW, to characterise the groundwater system and the water balance in the southern Jordan Valley. Furthermore, scenarios are simulated regarding hydrological conditions and management options, like extension of arable land and closure of illegal wells, influencing the projection of groundwater extraction. A limited dataset, literature values, field surveys, and the `crop water-requirement method' are combined to determine boundary conditions, aquifer parameters, and sources and sinks. The model results show good agreement between predicted and observed values; groundwater-level contours agree with the conceptual model and expected flow direction, and, in terms of water balance, flow volumes are in accordance with literature values. Average annual water consumption for irrigation is estimated to be 29 million m3 and simulation results show that a reduction of groundwater pumping by 40% could recover groundwater heads, reducing the water taken from storage. This study presents an example of how to develop a local numerical groundwater model to support management strategies under the condition of data scarcity.

  14. Modelling groundwater over-extraction in the southern Jordan Valley with scarce data

    NASA Astrophysics Data System (ADS)

    Alfaro, Paulina; Liesch, Tanja; Goldscheider, Nico

    2017-08-01

    To deal with the challenge of groundwater over-extraction in arid and semi-arid environments, it is necessary to establish management strategies based on the knowledge of hydrogeological conditions, which can be difficult in places where hydrogeological data are dispersed, scarce or present potential misinformation. Groundwater levels in the southern Jordan Valley (Jordan) have decreased drastically in the last three decades, caused by over-extraction of groundwater for irrigation purposes. This study presents a local, two-dimensional and transient numerical groundwater model, using MODFLOW, to characterise the groundwater system and the water balance in the southern Jordan Valley. Furthermore, scenarios are simulated regarding hydrological conditions and management options, like extension of arable land and closure of illegal wells, influencing the projection of groundwater extraction. A limited dataset, literature values, field surveys, and the `crop water-requirement method' are combined to determine boundary conditions, aquifer parameters, and sources and sinks. The model results show good agreement between predicted and observed values; groundwater-level contours agree with the conceptual model and expected flow direction, and, in terms of water balance, flow volumes are in accordance with literature values. Average annual water consumption for irrigation is estimated to be 29 million m3 and simulation results show that a reduction of groundwater pumping by 40% could recover groundwater heads, reducing the water taken from storage. This study presents an example of how to develop a local numerical groundwater model to support management strategies under the condition of data scarcity.

  15. Thermal history of rocks in southern San Joaquin Valley, California: evidence from fission-track analysis

    USGS Publications Warehouse

    Naeser, N.D.; Naeser, C.W.; McCulloh, T.H.

    1990-01-01

    Fission-track analysis has been used to study the thermal and depositional history of the subsurface Tertiary sedimentary rocks on both sides of the active White Wolf reverse fault in the southern San Joaquin Valley. The distinctly different thermal histories of the rocks in the two structural blocks are clearly reflected in the apatite fission-track data, which suggest that rocks in the rapidly subsiding basin northwest of the fault have been near their present temperature for only about 1 m.y. compared with about 10 m.y. for rocks southeast of the fault. These estimates of heating time agree with previous estimates for these rocks. Zircon fission-track data indicate that the Tertiary sediments were derived from parent rocks of more than one age. However, from at least the Eocene to late Miocene or Pliocene, the major sediment source was rocks related to the youngest Sierra Nevada Mesozoic intrusive complexes, which are presently exposed east and south of the southern San Joaquin Valley. -from Authors

  16. Morphological properties of tunnel valleys of the southern sector of the Laurentide Ice Sheet and implications for their formation

    NASA Astrophysics Data System (ADS)

    Livingstone, Stephen J.; Clark, Chris D.

    2016-07-01

    Tunnel valleys have been widely reported on the bed of former ice sheets and are considered an important expression of subglacial meltwater drainage. Although known to have been cut by erosive meltwater flow, the water source and development of channels has been widely debated; ranging between outburst flood events through to gradually occurring channel propagation. We have mapped and analysed the spatial pattern and morphometry of tunnel valleys and associated glacial landforms along the southern sector of the former Laurentide Ice Sheet from high-resolution digital elevation models. Around 2000 tunnel valleys have been mapped, revealing an organised pattern of sub-parallel, semi-regularly spaced valleys that form in distinctive clusters. The tunnel valleys are typically < 20 km long, and 0.5-3 km wide, although their width varies considerably down-valley. They preferentially terminate at moraines, which suggests that formation is time dependent; while we also observe some tunnel valleys that have grown headwards out of hill-hole pairs. Analysis of cross-cutting relationships between tunnel valleys, moraines and outwash fans permits reconstruction of channel development in relation to the retreating ice margin. This palaeo-drainage reconstruction demonstrates incremental growth of most valleys, with some used repeatedly or for long periods, during deglaciation, while others were abandoned shortly after their formation. Our data and interpretation support gradual (rather than a single-event) formation of most tunnel valleys with secondary contributions from flood drainage of subglacial and or supraglacially stored water down individual tunnel valleys. The distribution and morphology of tunnel valleys is shown to be sensitive to regional factors such as basal thermal regime, ice and bed topography, timing and climate.

  17. Late Cenozoic crustal extension and magmatism, southern Death Valley region, California

    USGS Publications Warehouse

    Calzia, J.P.; Rämö, O.T.

    2000-01-01

    The late Cenozoic geologic history of the southern Death Valley region is characterized by coeval crustal extension and magamatism. Crustal extension is accommodated by numerous listric and planar normal faults as well as right- and left-lateral strike slip faults. The normal faults sip 30°-50° near the surface and flatten and merge leozoic miogeoclinal rocks; the strike-slip faults act as tear faults between crustal blocks that have extended at different times and at different rates. Crustal extension began 13.4-13.1 Ma and migrated northwestward with time; undeformed basalt flows and lacustrine deposits suggest that extension stopped in this region (but continued north of the Death Valley graben) between 5 and 7 Ma. Estimates of crustal extension in this region vary from 30-50 percent to more than 100 percent. Magmatic rocks syntectonic with crustal extension in the southern Death Valley region include 12.4-6.4 Ma granitic rocks as well as bimodal 14.0-4.0 Ma volcanic rocks. Geochemical and isotopic evidence suggest that the granitic rocks get younger and less alkalic from south to north; the volcanic rocks become more mafic with less evidence of crustal interaction as they get younger. The close spatial and temporal relation between crustal extension and magmatism suggest a genetic and probably a dynamic relation between these geologic processes. We propose a rectonic-magmatic model that requires heat to be transported into the crust by mantle-derived mafic magmas. These magmas pond at lithologic or rheologic boundaries, begin the crystallize, and partially melt the surrounding crustal rocks. With time, the thermally weakened crust is extended (given a regional extensional stress field) concurrent with granitic magmatism and bimodal volcanism.

  18. Eclogite nappe-stack in the Grivola-Urtier Ophiolites (Southern Aosta Valley, Western Alps)

    NASA Astrophysics Data System (ADS)

    Tartarotti, Paola

    2013-04-01

    In the Western Alpine chain, ophiolites represent a section of the Mesozoic Tethys oceanic lithosphere, involved in subduction during the convergence between the paleo-Africa and paelo-Europe continents during the Cretaceous - Eocene. The Western Alpine ophiolites consist of several tectonic units, the most famous being the Zermatt-Saas and Combin nappes, and other major ophiolite bodies as the Voltri, Monviso, and Rocciavrè that show different rock assemblages and contrasting metamorphic imprints. The Grivola-Urtier (GU) unit is exposed in the southern Aosta Valley, covering an area of about 100 km2; it is tectonically sandwiched between the continentally-derived Pennidic Gran Paradiso Nappe below, and the Austroalpine Mount Emilius klippe above. This unit has been so far considered as part of the Zermatt-Saas nappe extending from the Saas-Fee area (Switzerland) to the Aosta Valley (Italy). The GU unit consists of serpentinized peridotites that include pods and boudinaged layers of eclogitic Fe-metagabbro and trondhjemite, rodingites and chloriteschists transposed in the main foliation together with calcschists and micaschists. All rocks preserve particularly fresh eclogitic mineral assemblages. The contact between the serpentinites and calcshists is marked by a tectonic mélange consisting of mylonitic marble and calcschist with stretched and boudinaged serpentinite blocks. Continentally-derived allochthonous blocks ranging in size from100 meters to meters are also included within the ophiolites. New field, petrographic and geochemical data reveal the complex nature of the fossil Tethyan oceanic lithosphere exposed in the southern Aosta Valley, as well as the extent and size of the continental-oceanic tectonic mélange. The geological setting of the GU unit is here inferred as a key tool for understanding the complex architecture of the ophiolites in the Western Alps.

  19. Paleontologic investigations of the uppermost Santa Susana Formation, south side of Simi Valley, southern California

    SciTech Connect

    Squires, R.L. )

    1991-02-01

    Strata assignable to the provincial macroinvertebrate Meganos stage, equivalent to the calcareous nannofossil CP8 zone (late Paleocene) to CP9 zone (early Eocene), are uncommon on the Pacific coast of North America. This stage has been recognized in southern California only in the uppermost Santa Susana Formation, north side of Simi Valley. Although early workers reported meganos stage strata from the south side of Simi Valley, most of these deposits have since been assigned to younger or older stages. Intensive collecting by the author now proves that Meganos stage fossils are present in the upper 100 m of the Santa Susana Formation on the south side of the Simi Valley, east of the Runkle Canyon fault. This 100-m-thick interval consists of gray, very fine-grained sandstone that has a gradational lithology from the underlying gray mudstone. Calcareous nannofossils were found only near the bottom of the 100-m-thick interval, and they are suggestive of the late Paleocene Discoaster multiradiatus (CP8) zone. Rare, macrofossil-bearing lenses near the bottom of the 100-m-thick interval contain the solitary coral Trochocyathus zitteli, the gastropods Turritella subuvasana and the Velates californicus( ), and the bivalve Fimbria susanensis. Sparsely occurring, macrofossil-bearing lenses in the upper 20 m of the 100-m-thick- interval contain the colonial coral Archohelia clarki and the gastropod Turritella andersoni susanae (= T. andersoni n. subsp. of authors). Turritella andersoni susanae indicates the early Eocene part of the Meganoz stage because it is found just above the earliest Eocene Discoaster diastypus (CP9) zone in the upper Santa Susana Formation on the north side of Simi Valley.

  20. New Record of Phlebotomus Sergenti, the Vector of Leishmania Tropica, in the Southern Nile Valley of Egypt

    DTIC Science & Technology

    2001-01-01

    SCIENTIFIC NOTE NEW RECORD OF PHLEBOTOMUS SERGENTI, THE VECTOR OF LEISHMANIA TROPICA , IN THE SOUTHERN NILE VALLEY OF EGYPT HANAFI A. HANAFI’ GREGORY M...forms of Leishmania tropica , from southern Egypt . Four female and I male P. sergenti were collected from unlit Centers for Disease Control light traps...sergenti (Parrot) is a widely distrib- uted sand fly species that feeds readily on humans and is a known vector of Leishmania tropica (Ash- ford and

  1. Eco-climatic Conditions Associated with Rift Valley fever Activity in Southern Africa in 2008-2011

    USDA-ARS?s Scientific Manuscript database

    The time period 2008-2011 has been marked by a series of Rift Valley fever (RVF) outbreaks in Southern Africa. These multi-year episodes of RVF have not occurred in the region since the mid-1970s. We examine climatic and ecological conditions associated with the outbreaks and present results of our ...

  2. Prediction, Assessment of the Rift Valley Fever Activity in East and Southern Africa 2006 - 2008 and Possible Vector Control Strategies

    USDA-ARS?s Scientific Manuscript database

    Historical episodic outbreaks of Rift Valley fever (RVF) since the early 1950s have been associated with cyclical patterns (El Niño and La Niña) of El Niño Southern Oscillation (ENSO) phenomenon which results in elevated and widespread rainfall over the RVF endemic areas of Africa. Using satellite ...

  3. Prediction, Assessment of the Rift Valley fever Activity in East and Southern Africa 2006 - 2008 and Possible Vector Control Strategies

    USDA-ARS?s Scientific Manuscript database

    Historical outbreaks of Rift Valley fever (RVF) since the early 1950s have been associated with cyclical patterns of the El Nino/Southern Oscillation (ENSO) phenomenon which results in elevated and widespread rainfall over the RVF endemic areas of Africa. Using satellite measurements of global and ...

  4. Factors Motivating Latino College Students to Pursue STEM Degrees on CSU Campuses in the Southern San Joaquin Valley

    ERIC Educational Resources Information Center

    Ramirez, Gabriel

    2014-01-01

    The purpose of this study was to determine what factors were motivating Latino/a students in the southern San Joaquin Valley to pursue STEM degrees and whether these factors were specific to the Latino/a culture. A 12-question survey was administered to STEM majors at California State University, Bakersfield and California State University, Fresno…

  5. Prediction, Assessment of the Rift Valley fever Activity in East and Southern Africa 2006 - 2008 and Possible Vector Control Strategies

    USDA-ARS?s Scientific Manuscript database

    Historical outbreaks of Rift Valley fever (RVF) since the early 1950s have been associated with cyclical patterns of the El Nino/Southern Oscillation (ENSO) phenomenon which results in elevated and widespread rainfall over the RVF endemic areas of Africa. Using satellite measurements of global and ...

  6. Yield, pollination aspects and kernel qualities of almond (Prunus amygdalus Batsch) selections trialed in the Southern San Joaquin Valley

    USDA-ARS?s Scientific Manuscript database

    A field trial was established in the Southern San Joaquin Valley to determine yield potential for nine almond selections grown under commercial conditions. Kernel yields were first quantified in 2008, at the end of the third growing season, and continued through the 2010 harvest. Harvested tonnage...

  7. Gwembe Coal Formation, Karoo Supergroup, Mid-Zambezi valley, southern Zambia; a fluvial plain environment

    SciTech Connect

    Nyambe, I.A.; Dixon, O. )

    1993-03-01

    The Gwembe Coal Formation of Permian age belongs to the Lower Karoo Group of the Karoo Supergroup (Permo-Carboniferous to early Jurassic), which crops out in the mid-Zambezi Valley, southern Zambia. The formation has a maximum thickness of 280 m. It was formed in a fluvial depositional environment in which sandstones, siltstones and mudstones were deposited in channels and flood plains. One sandstone body (A Sandstone) indicates a change in fluvial style from a proximal braided system to a high-sinuosity meandering stream system. The productive coals (Main Seam) with thicknesses from 5 to 12 m were deposited in shallow swampy areas of the flood plain. Peat deposition was interrupted by channel, crevasse channel and splay, levee and overbank deposition. Rootlets observed in basal sandstones indicate an insitu origin for the Main Seam.

  8. Impacts of changing irrigation practices on waterfowl habitat use in the southern San Joaquin Valley, California

    USGS Publications Warehouse

    Barnum, D.A.; Euliss, N. H .

    1991-01-01

    We used diurnal aerial census data to examine habitat use patterns of ducks wintering in the southern San Joaquin Valley, California from 1980-87. We calculated densities (birds/ha) for the northern pintail (Anas acuta), mallard (A. platyrhynchos), green-winged teal (A. crecca), cinnamon teal (A. cyanoptera), shoveler (A. clypeata), ruddy duck (Oxyura jamaicensis), and total ducks in each of 5 habitats. Densities of pintail and total ducks were greater in September than in other months. From October through January, density of teal and total ducks was greatest on Kern National Wildlife Refuge (NWR). Densities of ruddy duck and pintail were greatest on agricultural drainwater evaporation ponds and preirrigated cropland, respectively.

  9. Active tectonics of the Imperial Valley, southern California: fault damage zones, complex basins and buried faults

    NASA Astrophysics Data System (ADS)

    Persaud, P.; Ma, Y.; Stock, J. M.; Hole, J. A.; Fuis, G. S.; Han, L.

    2016-12-01

    Ongoing oblique slip at the Pacific-North America plate boundary in the Salton Trough produced the Imperial Valley. Deformation in this seismically active area is distributed across a complex network of exposed and buried faults resulting in a largely unmapped seismic hazard beneath the growing population centers of El Centro, Calexico and Mexicali. To better understand the shallow crustal structure in this region and the connectivity of faults and seismicity lineaments, we used data primarily from the Salton Seismic Imaging Project (SSIP) to construct a P-wave velocity profile to 15 km depth, and a 3-D velocity model down to 8 km depth including the Brawley Geothermal area. We obtained detailed images of a complex wedge-shaped basin at the southern end of the San Andreas Fault system. Two deep subbasins (VP <5.65 km/s) are located in the western part of the larger Imperial Valley basin, where seismicity trends and active faults play a significant role in shaping the basin edge. Our 3-D VP model reveals previously unrecognized NE-striking cross faults that are interacting with the dominant NW-striking faults to control deformation. New findings in our profile include localized regions of low VP (thickening of a 5.65-5.85 km/s layer) near faults or seismicity lineaments interpreted as possibly faulting-related. Our 3-D model and basement map reveal velocity highs associated with the geothermal areas in the eastern valley. The improved seismic velocity model from this study, and the identification of important unmapped faults or buried interfaces will help refine the seismic hazard for parts of Imperial County, California.

  10. Geochemical evidence for seasonal controls on the transportation of Holocene loess, Matanuska Valley, southern Alaska, USA

    USGS Publications Warehouse

    Muhs, Daniel; Budahn, James R.; Skipp, Gary L.; McGeehin, John

    2016-01-01

    Loess is a widespread Quaternary deposit in Alaska and loess accretion occurs today in some regions, such as the Matanuska Valley. The source of loess in the Matanuska Valley has been debated for more than seven decades, with the Knik River and the Matanuska River, both to the east, being the leading candidates and the Susitna River, to the west, as a less favorable source. We report here new stratigraphic, mineralogic, and geochemical data that test the competing hypotheses of these river sources. Loess thickness data are consistent with previous studies that show that a source or sources lay to the east, which rules out the Susitna River as a source. Knik and Matanuska River silts can be distinguished using Sc–Th–La, LaN/YbN vs. Eu/Eu∗, Cr/Sc, and As/Sb. Matanuska Valley loess falls clearly within the range of values for these ratios found in Matanuska River silt. Dust storms from the Matanuska River are most common in autumn, when river discharge is at a minimum and silt-rich point bars are exposed, wind speed from the north is beginning to increase after a low-velocity period in summer, snow depth is still minimal, and soil temperatures are still above freezing. Thus, seasonal changes in climate and hydrology emerge as critical factors in the timing of aeolian silt transport in southern Alaska. These findings could be applicable to understanding seasonal controls on Pleistocene loess accretion in Europe, New Zealand, South America, and elsewhere in North America.

  11. Postcrystalline deformation of the Pelona Schist bordering Leona Valley, southern California

    USGS Publications Warehouse

    Evans, James George

    1978-01-01

    Detailed structural investigations in part of the Leona Valley segment of the San Andreas fault zone, 5-16 km west of Palm dale, focused on the postcrystalline deformation of the block of Mesozoic(?) Pelona Schist underlying Portal and Ritter Ridges. The early fabric of the schist is modified and in places obliterated by cataclasis along shear zones near the San Andreas fault and the Hitchbrook fault, a major west-striking branch of the San Andreas fault system. Anastomosing shear foliations, fabric elements of the postcrystalline deformation, intersect at small angles to one another and are generally vertical or steeply dipping to the north-northeast; they are subparallel to the Hitchbrook fault. Many of these shear foliations are nearly parallel to the compositional layering and schistosity, which commonly dip at moderately steep angles to the northwest. Folds in the shear foliation, commonly intrafolial, generally plunge at moderately steep angles to the north-northeast or are nearly vertical. Other folds, various in form, have axes parallel to the intersections of the early schistosity and the shear foliations and plunge in many other directions. Faults, roughly similar in orientation to the shear foliations, have orientations subparallel to large-scale structures and structural features in the Leona Valley area and in southern California: the San Andreas fault zone in Leona Valley, the Hitchbrook fault, the Garlock fault zone, steep northward-striking faults, the San Andreas fault zone north and south of the Transverse Ranges, and the generally northwest-dipping early compositional layering of the schist. Slickensides on some of the minor faults indicate that the latest movements on the steep faults are predominantly strike slip with indications of less common episodes of predominantly dip slip. The low-angle faults have oblique slip with a large dip component.

  12. Geochemical evidence for seasonal controls on the transportation of Holocene loess, Matanuska Valley, southern Alaska, USA

    NASA Astrophysics Data System (ADS)

    Muhs, Daniel R.; Budahn, James R.; Skipp, Gary L.; McGeehin, John P.

    2016-06-01

    Loess is a widespread Quaternary deposit in Alaska and loess accretion occurs today in some regions, such as the Matanuska Valley. The source of loess in the Matanuska Valley has been debated for more than seven decades, with the Knik River and the Matanuska River, both to the east, being the leading candidates and the Susitna River, to the west, as a less favorable source. We report here new stratigraphic, mineralogic, and geochemical data that test the competing hypotheses of these river sources. Loess thickness data are consistent with previous studies that show that a source or sources lay to the east, which rules out the Susitna River as a source. Knik and Matanuska River silts can be distinguished using Sc-Th-La, LaN/YbN vs. Eu/Eu∗, Cr/Sc, and As/Sb. Matanuska Valley loess falls clearly within the range of values for these ratios found in Matanuska River silt. Dust storms from the Matanuska River are most common in autumn, when river discharge is at a minimum and silt-rich point bars are exposed, wind speed from the north is beginning to increase after a low-velocity period in summer, snow depth is still minimal, and soil temperatures are still above freezing. Thus, seasonal changes in climate and hydrology emerge as critical factors in the timing of aeolian silt transport in southern Alaska. These findings could be applicable to understanding seasonal controls on Pleistocene loess accretion in Europe, New Zealand, South America, and elsewhere in North America.

  13. Latest Pleistocene and Holocene glacial events in the Colonia valley, Northern Patagonia Icefield, southern Chile

    USGS Publications Warehouse

    Nimick, David A.; Mcgrath, Daniel; Mahan, Shannon; Friesen, Beverly A.; Leidich, Jonathan

    2016-01-01

    The Northern Patagonia Icefield (NPI) is the primary glaciated terrain worldwide at its latitude (46.5–47.5°S), and constraining its glacial history provides unique information for reconstructing Southern Hemisphere paleoclimate. The Colonia Glacier is the largest outlet glacier draining the eastern NPI. Ages were determined using dendrochronology, lichenometry, radiocarbon, cosmogenic 10Be and optically stimulated luminescence. Dated moraines in the Colonia valley defined advances at 13.2 ± 0.95, 11.0 ± 0.47 and 4.96 ± 0.21 ka, with the last being the first constraint on the onset of Neoglaciation for the eastern NPI from a directly dated landform. Dating in the tributary Cachet valley, which contains an ice-dammed lake during periods of Colonia Glacier expansion, defined an advance at ca. 2.95 ± 0.21 ka, periods of advancement at 810 ± 49 cal a BP and 245 ± 13 cal a BP, and retreat during the intervening periods. Recent Colonia Glacier thinning, which began in the late 1800s, opened a lower-elevation outlet channel for Lago Cachet Dos in ca. 1960. Our data provide the most comprehensive set of Latest Pleistocene and Holocene ages for a single NPI outlet glacier and expand previously developed NPI glacial chronologies.

  14. A 2.5 Myr-Old Canyon Beneath the Yarlung Tsangpo Valley, Southern Tibet

    NASA Astrophysics Data System (ADS)

    Scherler, D.; Wang, P.; Liu, J.; Mey, J.; Avouac, J. P.; Zhang, Y.; Shi, D.

    2014-12-01

    Orogenic plateaus like Tibet form when rock uplift and lateral tectonic growth outpace the headward incision of rivers. Although it is generally acknowledged that drainage systems concurrently reorganize, the patterns, timing, and causes of such events are usually poorly defined. Here we report the discovery of a deeply incised canyon of the Yarlung Tsangpo, at the eastern end of the Himalaya, which is now buried under >500m of sediments. Five drillings have recently been conducted at distances of up to 300 km upstream from the Tsangpo Gorge. Each drilling reached bedrock after penetrating through unconsolidated sediments and allowed us to reconstruct the former valley bottom. Results show that prior to aggradation, the Yarlung Tsangpo was able to erode back into the Tibetan Plateau and to develop a nearly graded profile. Cosmogenic nuclide derived burial ages from the base of the valley fill suggest that aggradation initiated at ~2-2.5 Ma. Our results provide clear evidence that accelerated uplift of the Namche Barwa and Gyala Peri massifs started ~2-2.5 Myr ago, blocked the canyon, and formed the modern Tsangpo Gorge. These findings refute existing hypotheses that relate the Tsangpo Gorge to young river capture or glacial damming during the Quaternary. We provide evidence for a similar and synchronous evolution of the Indus and Tsangpo Gorges, suggesting that the Himalayan syntaxes responded to a common forcing, possibly related to accelerated E-W extension of southern Tibet.

  15. Dog ownership, dog behaviour and transmission of Echinococcus spp. in the Alay Valley, southern Kyrgyzstan.

    PubMed

    Van Kesteren, Freya; Mastin, Alexander; Mytynova, Bermet; Ziadinov, Iskender; Boufana, Belgees; Torgerson, Paul R; Rogan, Michael T; Craig, Philip S

    2013-11-01

    Echinococcosis is a re-emerging zoonotic disease in Kyrgyzstan, and the incidence of human infection has increased substantially since the collapse of the Soviet Union in 1991. Domestic dogs are hosts of Echinococcus spp. and play an important role in the transmission of these parasites. The demography, ecology and behaviour of dogs are therefore relevant in studying Echinococcus spp. transmission. Dog demographics, roles of dogs, dog movements and faecal environmental contamination were assessed in four rural communities in the Alay Valley, southern Kyrgyzstan. Arecoline purge data revealed for the first time that E. granulosus, E. canadensis and E. multilocularis were present in domestic dogs in the Alay Valley. Surveys revealed that many households had dogs and that dogs played various roles in the communities, as pets, guard dogs or sheep dogs. Almost all dogs were free to roam, and GPS data revealed that many moved outside their communities, thus being able to scavenge offal and consume rodents. Faecal environmental contamination was high, presenting a significant infection risk to the local communities.

  16. Bioindicators from Mosquitofish (Gambusia affinis) Sampled from the Imperial Valley in Southern California

    USGS Publications Warehouse

    Jenkins, Jill A.; Draugelis-Dale, Rassa O.

    2006-01-01

    The Sonny Bono Salton Sea National Wildlife Refuge (SSNWR) is located 64 km north of the Mexican border at the southern end of the Salton Sea in California's Imperial Valley. Freshwater ponds and managed habitats at the SSNWR, Calipatria, Calif. are supplied with Colorado River water that carries compounds from upstream sources. Components include municipal and industrial discharges, agricultural drainage, and sewage plant inputs. Aquatic animals in these ecosystems are continuously exposed to multiple constituents, several of which have been demonstrated to be associated with hormonal disturbances. We investigated possible endocrine impacts to fish in the Imperial Valley, Calif., by addressing the null hypothesis that aquatic species in impacted sites did not exhibit evidence of endocrine disruption as compared with those from nonimpacted sites. The results presented are intended to provide managers with science-based information and interpretations about the condition of the animals in their ecosystems for the minimization of potential adverse effects to trust fish and wildlife resources and for the maximization of available water resources.

  17. Multi-scale electromagnetic imaging of the Monte Aquila Fault (Agri Valley, Southern Italy)

    NASA Astrophysics Data System (ADS)

    Giocoli, Alessandro; Piscitelli, Sabatino; Romano, Gerardo; Balasco, Marianna; Lapenna, Vincenzo; Siniscalchi, Agata

    2010-05-01

    The Agri Valley is a NW-SE trending intermontane basin formed during the Quaternary times along the axial zone of the Southern Apennines thrust belt chain. This basin is about 30 Km long and 12 Km wide and is filled by Quaternary continental deposits, which cover down-thrown pre-Quaternary rocks of the Apennines chain. The Agri Valley was hit by the M 7.0, 1857 Basilicata earthquake (Branno et al., 1985), whose macroseismic field covered a wide sector of the Southern Apennines chain. The latest indications of Late Quaternary faulting processes in Agri Valley were reported in Maschio et al., (2005), which documented a unknown NE-dipping normal fault thanks to the finding of small-scale morphological features of recent tectonic activity. The identified structure was termed Monte Aquila Fault (MAF) and corresponds to the southern strand of the NW-SE trending Monti della Maddalena Fault System (Maschio et al., 2005; Burrato and Valensise, 2007). The NE-dipping MAF consists of a main northern segment, about 10 Km long, and two smaller segments with cumulate length of ~10 Km, thus bringing the total length to ~20 Km. The three segments are arranged in a right-stepping en-echelon pattern and are characterized by subtle geomorphic features. In order to provide more detailed and accurate information about the MAF, a strategy based on the application of complementary investigation tools was employed. In particular, multi-scale electromagnetic investigation, including Electrical Resistivity Tomography (ERT), Ground Penetrating Radar (GPR) and Magnetotelluric (MT) methods, was used to image the MAF from near-surface to several hundred metres depth. Large-scale MT investigation proved to be useful in detecting the MAF location down to several hundred meters depth, but it didn't show any shallow evidence about MAF. Conversely, ERT and GPR surveys evidenced signatures of normal-faulting activity at shallow depth (e.g., back-tilting of the bedrock, colluvial wedges, etc.). In

  18. Ground water in the Eugene-Springfield area, southern Willamette Valley, Oregon

    USGS Publications Warehouse

    Frank, F.J.

    1973-01-01

    The cities of Eugene and Springfield and their outlying suburban and rural districts constitute an area of rapid population growth where progressively greater volumes of ground water are being required for irrigation and industrial and public supplies. The area is also one of diverse geologic and hydrologic conditions. As used in this report, the Eugene-Springfield area covers about 450 square miles and includes a part of the lower foothills of the Coast and Cascade Ranges and a strip of the main valley plain of the southern Willamette Valley. Volcanic and sedimentary rock units exposed in the foothills range in age from Eocene to Miocene. In the main valley plain the older units are overlain by Pleistocene and Holocene alluvial deposits. Marine-deposited sandstone, siltstone, shale, and mudstone of the older sedimentary units are fine grained and poorly permeable and yield water slowly to wells. The volcanic rocks, primarily of dacitic and andesitic composition, yield small quantities of water that are generally adequate only for domestic use. The alluvial deposits (sand and gravel) of the valley plain (central lowland) contain the most productive aquifers in the area and are considered to be the only ground-water reservoir for which large-scale development of ground-water supplies is feasible. Aquifers in the area are recharged principally by direct infiltration of precipitation. Most of the precipitation, which averages about 4C inches per year, occurs during late autumn and winter. Minimum recharge by infiltration of precipitation to the alluvial aquifers beneath the valley plain is estimated to be about 100,000 acre-feet. Ground water is discharged naturally from the central lowland by seepage and spring flow to small streams, by subsurface outflow to adjacent areas, and by evapotranspiration. Storage capacity of the central lowland in the Eugene-Springfield area is estimated to be about 2.1 million acre-feet in the zone 10-150 feet below land surface. The

  19. Geodetic constraints on frictional properties and earthquake hazard in the Imperial Valley, Southern California

    NASA Astrophysics Data System (ADS)

    Lindsey, Eric O.; Fialko, Yuri

    2016-02-01

    We analyze a suite of geodetic observations across the Imperial Fault in southern California that span all parts of the earthquake cycle. Coseismic and postseismic surface slips due to the 1979 M 6.6 Imperial Valley earthquake were recorded with trilateration and alignment surveys by Harsh (1982) and Crook et al. (1982), and interseismic deformation is measured using a combination of multiple interferometric synthetic aperture radar (InSAR)-viewing geometries and continuous and survey-mode GPS. In particular, we combine more than 100 survey-mode GPS velocities with InSAR data from Envisat descending tracks 84 and 356 and ascending tracks 77 and 306 (149 total acquisitions), processed using a persistent scatterers method. The result is a dense map of interseismic velocities across the Imperial Fault and surrounding areas that allows us to evaluate the rate of interseismic loading and along-strike variations in surface creep. We compare available geodetic data to models of the earthquake cycle with rate- and state-dependent friction and find that a complete record of the earthquake cycle is required to constrain key fault properties including the rate-dependence parameter (a - b) as a function of depth, the extent of shallow creep, and the recurrence interval of large events. We find that the data are inconsistent with a high (>30 mm/yr) slip rate on the Imperial Fault and investigate the possibility that an extension of the San Jacinto-Superstition Hills Fault system through the town of El Centro may accommodate a significant portion of the slip previously attributed to the Imperial Fault. Models including this additional fault are in better agreement with the available observations, suggesting that the long-term slip rate of the Imperial Fault is lower than previously suggested and that there may be a significant unmapped hazard in the western Imperial Valley.

  20. Paleoseismic investigations of the Paintbrush Canyon fault in southern Midway Valley, Yucca Mountain, Nevada: Preliminary results

    SciTech Connect

    Swan, F.H.; Wesling, J.R.; Thomas, A.P. )

    1993-04-01

    Trench mapping in southern Midway Valley provides evidence of multiple surface-faulting events on a western splay of the Paintbrush Canyon fault during the middle to late Pleistocene. The 6-m-wide fault zone exposed in the trench strikes N30-45E and dips steeply ([approximately]78[degree]) to the west, although some shears within the zone dip to the east. Tertiary volcanic bedrock is exposed only on the footwall block within the trench. Unconsolidated colluvial and eolian deposits are present in the hanging-wall block and above bedrock in the footwall block. These deposits tentatively are assigned, respectively, mid Pleistocene and late Pleistocene ages based on correlations with surficial map units in Midway Valley. Three to five displacement events are inferred based on faulted colluvial and eolian deposits, and scarp-derived colluvial wedges. Total cumulative dip-slip displacement of the oldest middle Pleistocene subunit is estimated to be about 170 to 270 cm. The dip-slip displacement associated with the youngest event is about 15 cm. The earlier displacements are estimated to have produced between 40 and 85 cm of dip-slip displacement per event. The most recent event occurred after deposition of late Pleistocene colluvium deposited against the fault scarp but before deposition of an overlying hillslope-derived colluvium of probable late pleistocene age. Based on the preliminary results of the authors study, the middle to late Quaternary rate of dip-slip displacement is approximately 0.01 m/kyr or less. Ongoing work, including soil-stratigraphic studies and numerical dating of deposits, should better constrain the timing and a rate of faulting along this western splay of the Paintbrush Canyon fault.

  1. Estimating the permanent loss of groundwater storage in the southern San Joaquin Valley, California

    NASA Astrophysics Data System (ADS)

    Smith, R. G.; Knight, R.; Chen, J.; Reeves, J. A.; Zebker, H. A.; Farr, T.; Liu, Z.

    2017-03-01

    In the San Joaquin Valley, California, recent droughts starting in 2007 have increased the pumping of groundwater, leading to widespread subsidence. In the southern portion of the San Joaquin Valley, vertical subsidence as high as 85 cm has been observed between June 2007 and December 2010 using Interferometric Synthetic Aperture Radar (InSAR). This study seeks to map regions where inelastic (not recoverable) deformation occurred during the study period, resulting in permanent compaction and loss of groundwater storage. We estimated the amount of permanent compaction by incorporating multiple data sets: the total deformation derived from InSAR, estimated skeletal-specific storage and hydraulic parameters, geologic information, and measured water levels during our study period. We used two approaches, one that we consider to provide an estimate of the lowest possible amount of inelastic deformation, and one that provides a more reasonable estimate. These two approaches resulted in a spatial distribution of values for the percentage of the total deformation that was inelastic, with the former estimating a spatially averaged value of 54%, and the latter a spatially averaged value of 98%. The former corresponds to the permanent loss of 4.14 × 108 m3 of groundwater storage, or roughly 5% of the volume of groundwater used over the study time period; the latter corresponds to the loss of 7.48 × 108 m3 of groundwater storage, or roughly 9% of the volume of groundwater used. This study demonstrates that a data-driven approach can be used effectively to estimate the permanent loss of groundwater storage.

  2. Ground water in the Harrisburg-Halsey area, southern Willamette Valley, Oregon

    USGS Publications Warehouse

    Frank, F.J.

    1976-01-01

    The Harrisburg-Halsey area lies between the Cascade and Coast Ranges in the southern Willamette Valley in northwestern Oregon. The area consists of approximately 350 square miles (910 km2) and includes a part of the lower foothills of the Coast and Cascade Ranges. Volcanic and marine sedimentary units exposed in the foothills range in age from Eocene to Miocene. The volcanic rocks are primarily of dacitic and andesitic composition and yield only small quantities of water that are generally adequate only for domestic and stock use. The alluvial deposits (sand and gravel) of the valley plain contain the more productive aquifers in the area and yield most of the water that is pumped from wells in the area. Aquifers in the area are recharged principally by direct infiltration of precipitation. Most of the precipitation, which averages about 40 in. (1,020 mm) per year occurs during late autumn and winter. During 1974 the seasonal decline of water levels from winter to late summer averaged about 10 ft 13 m) for the alluvial deposits. The seasonal change of storage for 1974 was estimated to be about 170,000 acre-ft (210 hm3). Of this volume, about 14,300 acre-ft (17.6 hm3) was pumped from wells; the rest, about 156,000 acre-ft (190 hm3), was discharged naturally by seepage and spring flow to streams and by evapotranspiration. The difference between pumpage and natural discharge indicates that a large quantity of additional water is available for development. The storage capacity of the alluvial aquifers is estimated to be about 800,000 acre-ft (1,000 hm3) in the zone 10-100 ft (3-30 m} below land surface. Ground water from the alluvial deposits is chemically suitable for irrigation and other uses, as is most of the water obtained from perched-water bodies in the older sedimentary and volcanic rocks. However, the mineral concentration of water from the older sedimentary rocks, particularly from deeper producing zones beneath the valley plain, is greater than that of water

  3. The effect of pumping large-discharge wells on the ground-water reservoir in southern Utah Valley, Utah County, Utah

    USGS Publications Warehouse

    Cordova, R.M.; Mower, R.W.

    1967-01-01

    An extensive aquifer test in southern Utah Valley, Utah County, Utah, was made during January-March 1967 by the U.S. Geological Survey in cooperation with the Utah State Engineer. The purpose of the test was to obtain data about the hydraulic characteristics of the aquifer in the valley and to determine whether pumping large-diameter wells decreased artesian pressures and resulting flow from the numerous small-diameter flowing wells in the valley (fig. 1).

  4. Holocene loess deposition and soil formation as competing processes, Matanuska Valley, southern Alaska

    USGS Publications Warehouse

    Muhs, D.R.; McGeehin, J.P.; Beann, J.; Fisher, E.

    2004-01-01

    Although loess-paleosol sequences are among the most important records of Quaternary climate change and past dust deposition cycles, few modern examples of such sedimentation systems have been studied. Stratigraphic studies and 22 new accelerator mass spectrometry radiocarbon ages from the Matanuska Valley in southern Alaska show that loess deposition there began sometime after ???6500 14C yr B.P. and has continued to the present. The silts are produced through grinding by the Matanuska and Knik glaciers, deposited as outwash, entrained by strong winds, and redeposited as loess. Over a downwind distance of ???40 km, loess thickness, sand content, and sand-plus-coarse-silt content decrease, whereas fine-silt content increases. Loess deposition was episodic, as shown by the presence of paleosols, at distances >10 km from the outwash plain loess source. Stratigraphic complexity is at a maximum (i.e., the greatest number of loesses and paleosols) at intermediate (10-25 km) distances from the loess source. Surface soils increase in degree of development with distance downwind from the source, where sedimentation rates are lower. Proximal soils are Entisols or Inceptisols, whereas distal soils are Spodosols. Ratios of mobile CaO, K2O, and Fe2O3 to immobile TiO2 show decreases in surface horizons with distance from the source. Thus, as in China, where loess deposition also takes place today, eolian sedimentation and soil formation are competing processes. Study of loess and paleosols in southern Alaska shows that particle size can vary over short distances, loess deposition can be episodic over limited time intervals, and soils developed in stabilized loess can show considerable variability under the same vegetation. ?? 2004 University of Washington. All rights reserved.

  5. Epidemiologic and Environmental Risk Factors of Rift Valley Fever in Southern Africa from 2008 to 2011

    PubMed Central

    Glancey, Margaret M.; Linthicum, Kenneth J.

    2015-01-01

    Abstract Background: Rift Valley fever (RVF) outbreaks have been associated with periods of widespread and above-normal rainfall over several months. Knowledge on the environmental factors influencing disease transmission dynamics has provided the basis for developing models to predict RVF outbreaks in Africa. From 2008 to 2011, South Africa experienced the worst wave of RVF outbreaks in almost 40 years. We investigated rainfall-associated environmental factors in southern Africa preceding these outbreaks. Methods: RVF epizootic records obtained from the World Animal Health Information Database (WAHID), documenting livestock species affected, location, and time, were analyzed. Environmental variables including rainfall and satellite-derived normalized difference vegetation index (NDVI) data were collected and assessed in outbreak regions to understand the underlying drivers of the outbreaks. Results: The predominant domestic vertebrate species affected in 2008 and 2009 were cattle, when outbreaks were concentrated in the eastern provinces of South Africa. In 2010 and 2011, outbreaks occurred in the interior and southern provinces affecting over 16,000 sheep. The highest number of cases occurred between January and April but epidemics occurred in different regions every year, moving from the northeast of South Africa toward the southwest with each progressing year. The outbreaks showed a pattern of increased rainfall preceding epizootics ranging from 9 to 152 days; however, NDVI and rainfall were less correlated with the start of the outbreaks than has been observed in eastern Africa. Conclusions: Analyses of the multiyear RVF outbreaks of 2008 to 2011 in South Africa indicated that rainfall, NDVI, and other environmental and geographical factors, such as land use, drainage, and topography, play a role in disease emergence. Current and future investigations into these factors will be able to contribute to improving spatial accuracy of models to map risk areas

  6. Gravity and magnetic data in the vicinity of Virgin Valley, southern Nevada

    USGS Publications Warehouse

    Morin, Robert L.

    2006-01-01

    This report contains 10 interpretive cross sections and an integrated text describing the geology of parts of the Colorado, White River, and Death Valley regional ground-water flow systems, Nevada, Utah, and Arizona. The primary purpose of the report is to provide geologic framework data for input into a numerical ground-water model. Therefore, the stratigraphic and structural summaries are written in a hydrogeologic context. The oldest rocks (basement) are Early Proterozoic metamorphic and intrusive crystalline rocks that are considered confining units because of their low permeability. Late Proterozoic to Lower Cambrian clastic units overlie the crystalline rocks and are also considered confining units within the regional flow systems. Above the clastic units are Middle Cambrian to Lower Permian carbonate rocks that are the primary aquifers in the flow systems. The Middle Cambrian to Lower Permian carbonate rocks are overlain by a sequence of mainly clastic rocks of late Paleozoic to Mesozoic age that are mostly considered confining units, but they may be permeable where faulted. Tertiary volcanic and plutonic rocks are exposed in the northern and southern parts of the study area. In the Clover and Delamar Mountains, these rocks are highly deformed by north- and northwest-striking normal and strike-slip faults that are probably important conduits in transmitting ground water from the basins in the northern Colorado and White River flow systems to basins in the southern part of the flow systems. The youngest rocks in the region are Tertiary to Quaternary basin-fill deposits. These rocks consist of middle to late Tertiary sediments consisting of limestone, conglomerate, sandstone, tuff, and gypsum, and younger Quaternary surficial units consisting of alluvium, colluvium, playa deposits, and eolian deposits. Basin-fill deposits are both aquifers and aquitards.

  7. Strike-Slip displacement along the Furnace Creek Fault Zone, southern Basins and Ranges, Death Valley, California

    NASA Astrophysics Data System (ADS)

    Baucke, W.; Cemen, I.

    2007-12-01

    The southern Basins and Ranges contain several strike-slip fault zones in addition to predominant normal faults. One of the strike-slip faults is the Furnace Creek fault zone (FCFZ) which extends from the Amor¬gosa Valley in eastern California northwestward continuously about 200 km and termi¬nates in the Fish Lake Valley in Nevada. The fault zone is a part of the Eastern California Shear Zone. Although the right-lateral sense of strike-slip movement along the FCFZ is undisputed, the magnitude of displacement has been controversial since the 1970s. Recently, we have mapped conglomerates exposed in the Travertine point area of the Furnace Creek Wash of the Death Valley region. The conglomerates are composed of Paleozoic clasts from the following formations: Bonanza King, Nopah, Pogonip, Eureka Quartzite, Hidden Valley, and Ely Springs Dolomite. Our analysis of these breccias showed that they are made out of clasts of one composition and a matrix that was slightly different. This observation and our microscopic analysis suggest to us that these breccias were formed as fault breccias along the Furnace Creek fault zone. We have also mapped breccias in the Desolation Canyon on the southwestern side of the FCFZ where the Bonanza King Formation is brought into structural contact over the Ely Spring Dolomite and Eureka Quartzite suggesting the presence of a thrust fault. We correlate this thrust fault with a similar structural setting along the Clery Thrust of the southern Funeral Mountains on northeastern sides of the FCFZ where the Clery thrust brings the Cambrian Bonanza King Formation over the Eureka Quartzite and Ely Spring Dolomite in the southern Funeral Mountains. These observations suggest to us that the thrust fault in the Desolation Canyon area is the continuation of the Clery Thrust of the southern Funeral Mountains. If this interpretation is correct, the strike-slip displacement along the FCFZ is about 30 km.

  8. Striving for sustainable wildlife management: the case of Kilombero Game Controlled Area, Tanzania.

    PubMed

    Haule, K S; Johnsen, F H; Maganga, S L S

    2002-09-01

    The sustainability of wildlife resources in Africa is threatened by poaching for trophies and meat as well as changes in land use. In order to motivate local people for sustainable wildlife management, efforts to transfer decision-making power as well as benefits from central to local level have been made in several countries. Such efforts have not yet been seen in Kilombero Game Controlled Area, which is the area covered by the present study. The paper documents the importance of wildlife to local people, explores local people's perceptions on wildlife management and identifies constraints to sustainable wildlife management. A total of 177 household interviews in 5 villages and 129 interviews of pupils in schools have been conducted. The majority of pupils reported that their latest meal of meat was from a wild animal, and the most common species was buffalo. Apart from availability of cheap wildlife meat, advantages from living close to wildlife include the use of various parts of animals for, e.g. medical and ritual uses, and various plant products from wildlife habitats. Disadvantages include damages to crops, predation on livestock, and injuries to humans. The estimated loss of yield due to raiding by wildlife amounted to 21.9 and 47.8% of the harvest of rice and maize, respectively. Traditional wildlife management in Kilombero includes few rules to avoid resource depletion, because depletion has traditionally not been a problem due to low hunting technology and low human population. Government management includes strict rules, with hunting quotas as the main instrument, but the government has failed to enforce the rules. Ongoing discussions on new approaches to wildlife management like co-management and community-based management were largely unknown to the villagers in the area. Both poaching and agricultural expansion threaten the sustainability of Kilombero Game Controlled Area. It is suggested that transfers of decision-making power and benefits to local

  9. Mineralogical Characterization of the Miocene Olcese Formation, Southern San Joaquin Valley, California

    NASA Astrophysics Data System (ADS)

    Lopez, K. A.; Baron, D.; Guo, J.; Woolford, J. M.

    2016-12-01

    The early to middle Miocene Olcese Formation in the southern San Joaquin Valley of California consists of shallow marine shelf sands in its lower and upper parts, and non-marine, frequently pumiceous sands in its middle part, and varies in thickness up to 1800 ft. There is little known as to the origin, nature, quantity, and distribution of clay minerals throughout the formation. This study examined 95 sidewall core samples from three wells, as well as 388 cutting samples from four wells and 12 samples from 3 outcrops. Well samples were from depths between 1,800 and 4,000 ft. Qualitative and quantitative mineralogy including clay minerals of the sidewall samples and selected cutting samples was determined by powder X-ray diffraction (XRD). XRD analyses were supplemented by scanning electron microscopy with energy-dispersive X-ray spectroscopy (SEM-EDS) and petrographic microscopy of selected samples. The main minerals of bulk samples include composite clay, quartz, potassium feldspar/plagioclase, calcite, and clinoptilolite. Content of composite clay varies between 17% and 51%. The clay-size fraction is predominantly composed of smectite, illite, kaolinite and chlorite with smectite being the most abundant. Smectite and clinoptilolite may be the alteration products of deeper burial of volcanic materials. The formation permeability could be significantly lowered by these authigenic minerals.

  10. Late Quaternary incision and deposition in an active volcanic setting: The Volturno valley fill, southern Italy

    NASA Astrophysics Data System (ADS)

    Amorosi, Alessandro; Pacifico, Annamaria; Rossi, Veronica; Ruberti, Daniela

    2012-12-01

    Extensive illustration of depositional facies, ostracod and foraminiferal assemblages, and Late Quaternary stratigraphic architecture is offered for the first time from beneath the modern coastal plain of Volturno River, the longest river in southern Italy. Proximity to an active volcanic district, including quiescent Vesuvius Volcano, provides an easily identifiable stratigraphic marker (Campania Grey Tuff or CGT), up to 55 m thick, emplaced 39 ky cal BP by a large-volume explosive pyroclastic eruption. Identification of top CGT to a maximum depth of 30 m allows tracing out the shape of a 15-20 km wide Late Quaternary palaeovalley incised by Volturno River into the thick ignimbritic unit immediately after its deposition. A terraced palaeotopography of the valley flanks is reconstructed on the basis of core data. Above the basal fluvial deposits, the early Holocene transgressive facies consist of a suite of estuarine (freshwater to brackish) deposits. These are separated from overlying transgressive barrier sands by a distinctive wave ravinement surface. Upwards, a distinctive shallowing-upward succession of middle-late Holocene age is interpreted to reflect initiation and subsequent progradation of a wave-dominated delta system, with flanking strandplains, in response to reduced rate of sea-level rise. The turnaround from transgressive to highstand conditions is identified on the basis of subtle changes in the meiofauna. These enable tracking of the maximum flooding surface into its updip (lagoonal/estuarine) counterpart, thus highlighting the role of refined palaeontological criteria as a powerful tool for high-resolution sequence-stratigraphic studies.

  11. 1995 Integrated Monitoring Study: Fog measurements in the Southern San Joaquin Valley - preliminary results

    SciTech Connect

    Collett, J. Jr.; Bator, A.; Sherman, D.E.

    1996-12-31

    Fogs were sampled at three ground-based stations in the southern portion of California`s San Joaquin Valley as part of the winter component of the 1995 Integrated Monitoring Study (IMS95). The three sampling sites included two urban locations (Bakersfield and Fresno) and one rural location (near the Kern Wildlife Refuge). Both bulk and drop size-fractionated samples were collected at each site. Several fog events were sampled, with three periods of extensive fog coverage that included all three sampling sites. Results of preliminary data analysis are presented. Fog collected at the sites was generally quite basic. Most bulk fog samples had pH values above 6 reflecting strong inputs from ammonia. Occasional strong sulfur plumes at Bakersfield, however, tended to lower the fog pH. Aside from these periods, nitrate was generally present at much higher concentrations in the fog than sulfate. Decreases in fogwater loadings of major species over the course of one extended fog episode at Fresno suggest significant deposition was occurring to the surface, consistent with observations of substantial droplet fluxes to exposed surfaces during that period. 16 refs., 7 figs., 1 tab.

  12. Eliminating Rabies in Tanzania? Local Understandings and Responses to Mass Dog Vaccination in Kilombero and Ulanga Districts

    PubMed Central

    Bardosh, Kevin; Sambo, Maganga; Sikana, Lwitiko; Hampson, Katie; Welburn, Susan C.

    2014-01-01

    Background With increased global attention to neglected diseases, there has been a resurgence of interest in eliminating rabies from developing countries through mass dog vaccination. Tanzania recently embarked on an ambitious programme to repeatedly vaccinate dogs in 28 districts. To understand community perceptions and responses to this programme, we conducted an anthropological study exploring the relationships between dogs, society, geography and project implementation in the districts of Kilombero and Ulanga, Southern Tanzania. Methodology/Principal Findings Over three months in 2012, we combined the use of focus groups, semi-structured interviews, a household questionnaire and a population-based survey. Willingness to participate in vaccination was mediated by fear of rabies, high medical treatment costs and the threat of dog culling, as well as broader notions of social responsibility. However, differences between town, rural and (agro-) pastoralist populations in livelihood patterns and dog ownership impacted coverage in ways that were not well incorporated into project planning. Coverage in six selected villages was estimated at 25%, well below official estimates. A variety of problems with campaign mobilisation, timing, the location of central points, equipment and staff, and project organisation created barriers to community compliance. Resource-limitations and institutional norms limited the ability for district staff to adapt implementation strategies. Conclusions and Significance In the shadows of resource and institutional limitations in the veterinary sector in Africa, top-down interventions for neglected zoonotic diseases likes rabies need to more explicitly engage with project organisation, capacity and community participation. Greater attention to navigating local realities in planning and implementation is essential to ensuring that rabies, and other neglected diseases, are controlled sustainably. PMID:24945697

  13. Fertilisation of the Southern Atlantic: Ephemeral River Valleys as a replenishing source of nutrient-enriched mineral aerosols

    NASA Astrophysics Data System (ADS)

    Dansie, Andrew; Wiggs, Giles; Thomas, David

    2016-04-01

    Oceanic dust deposition provides biologically important iron and macronutrients (Phosphorus (P) and Nitrogen-based (N) compounds) that contribute to phytoplankton growth, marine productivity and oceanic atmospheric CO2 uptake. Research on dust emission sources to date has largely focused on the northern hemisphere and on ephemeral lakes and pans. Our work considers the ephemeral river valleys of the west coast of Namibia as an important yet overlooked source of ocean-fertilizing dust. Dust plumes are frequently emitted from the river valleys by strong easterly winds during the Southern Hemisphere winter, when the upwelling of the Benguela Current is at its weakest. We present field data from dust emission source areas along the main river channels near the coastal termini of the Huab, Kuiseb and Tsauchab river valleys. Collected data include erodible surface sediment, wind-blown flux, and associated meteorological data. Extensive surface sediment sampling was also undertaken throughout the combined 34,250 km2 extent of each river valley catchment with samples collected from within the main river channels, the main branches of each river system, selected tributaries, and into the upper watersheds. Geochemical data show valley sediment and wind-blown flux material have high concentrations of bioavailable Fe, P and N, exceeding that measured at the major dry lake basin dust sources in southern Africa. The contribution of fertilising deposition material is enhanced by both the spatial proximity of the source areas to the ocean and enrichment of source material by ephemeral fluvial accumulation and desiccation. Results show that geographical factors within each watershed play a key role in the nutrient composition of the emitting fluvial deposits in the river valleys. Analysis explores potential relationships between land use, geology, climate and precipitation in the upper watersheds and their influence on bioavailability of Fe, P and N compounds in wind

  14. Characterization of intrabasin faulting and deformation for earthquake hazards in southern Utah Valley, Utah, from high-resolution seismic imaging

    USGS Publications Warehouse

    Stephenson, William J.; Odum, Jack K.; Williams, Robert A.; McBride, John H.; Tomlinson, Iris

    2012-01-01

    We conducted active and passive seismic imaging investigations along a 5.6-km-long, east–west transect ending at the mapped trace of the Wasatch fault in southern Utah Valley. Using two-dimensional (2D) P-wave seismic reflection data, we imaged basin deformation and faulting to a depth of 1.4 km and developed a detailed interval velocity model for prestack depth migration and 2D ground-motion simulations. Passive-source microtremor data acquired at two sites along the seismic reflection transect resolve S-wave velocities of approximately 200 m/s at the surface to about 900 m/s at 160 m depth and confirm a substantial thickening of low-velocity material westward into the valley. From the P-wave reflection profile, we interpret shallow (100–600 m) bedrock deformation extending from the surface trace of the Wasatch fault to roughly 1.5 km west into the valley. The bedrock deformation is caused by multiple interpreted fault splays displacing fault blocks downward to the west of the range front. Further west in the valley, the P-wave data reveal subhorizontal horizons from approximately 90 to 900 m depth that vary in thickness and whose dip increases with depth eastward toward the Wasatch fault. Another inferred fault about 4 km west of the mapped Wasatch fault displaces horizons within the valley to as shallow as 100 m depth. The overall deformational pattern imaged in our data is consistent with the Wasatch fault migrating eastward through time and with the abandonment of earlier synextensional faults, as part of the evolution of an inferred 20-km-wide half-graben structure within Utah Valley. Finite-difference 2D modeling suggests the imaged subsurface basin geometry can cause fourfold variation in peak ground velocity over distances of 300 m.

  15. Inbreeding avoidance in an isolated indigenous Zapotec community in the valley of Oaxaca, southern Mexico.

    PubMed

    Little, Bertis B; Malina, Robert M

    2005-06-01

    We analyzed inbreeding using surname isonymy in an indigenous genetic isolate. The subjects were residents of a rural Zapotec-speaking community in the valley of Oaxaca, southern Mexico. The community can be classified as a genetic isolate with an average gene flow of < or = 3% per generation. Surnames were collected for individuals in each household in pedigree form using the culturally traditional patronym-matronym naming. Estimation of inbreeding from surname isonymy is facilitated by the traditional patronym-matronym name assignment among indigenous Mexican populations. A total of 2,149 individuals had valid surname patronym-matronym pairings, including 484 deceased ancestors. Surname isonymy analysis methods were used to estimate total inbreeding and to segregate it into random and nonrandom components. The surname isonymy coefficient computed from 119 isonymous surname pairings (119/2,149) was 0.0554. The estimated inbreeding coefficient from surname isonymy was 0.0138 (0.0554/4). The random and nonrandom components of inbreeding were F(r) = 0.0221 and F(n) = -0.0091, respectively. The results suggest that consanguinity is culturally avoided. Nonrandom inbreeding decreased total inbreeding by about 41%. Total estimated inbreeding by surname isonymy was 0.0138, which is similar to inbreeding estimated from a sample of pedigrees, 0.01. Socially prescribed inbreeding avoidance substantially lowered total F through negative nonrandom inbreeding. Even in the situation of genetic isolation and small effective population size (N(e)), estimated inbreeding is lower than may have otherwise occurred if inbreeding were only random. However, among the poorest individuals, socially prescribed jural rules for inbreeding avoidance failed to operate. Thus the preponderance of inbreeding appears to occur among the poor, economically disadvantaged in the community.

  16. Late Glacial and Holocene Record of Hydroclimate in the San Luis Valley, Southern Colorado, USA

    NASA Astrophysics Data System (ADS)

    Yuan, F.; Koran, M.

    2012-12-01

    Lake sediments from the San Luis Valley, south-central Colorado, archive a detailed record of Late Glacial and Holocene climatic fluctuations in the southern Rocky Mountains. Together with radiometric dating analysis, measurements of grain size, magnetic susceptibility, total inorganic carbon (TIC), oxygen and carbon isotopic composition of the TIC fraction on sediment samples from San Luis Lake (at an average resolution of 60 years per sample) allow us to generate a sediment record of climatic change in the region spanning the last 16ka (1 ka=1000 cal yrs). This record documents the timing and duration of major climate episodes and trends, comparable to the existing paleoclimate records from the American Southwest. The Late Glacial record of San Luis Lake contains a big wet episode in the late part of the Mystery Interval (MI), a relatively dry climate during Bølling-Allerød (B/A) warm interval, and a relatively wet episode during the Younger Dryas (YD) interval, similar to the lake-level record found in the Estancia basin in central New Mexico. The early to middle Holocene record of d18O in the San Luis Lake parallels the calcite d18O record of Bison Lake in northern Colorado, documenting a history of significant change in precipitation seasonality across the northern boundary of the North American monsoon (NAM). The middle Holocene epoch is characterized by greater variations in magnetic susceptibility, d18O and d13C, suggesting the prevalence of wet, variable or transitional climate conditions. In contrast, the late Holocene climate is relatively dry, as indicated by more positive values of d18O in San Luis Lake. The results of this study reveal a complex history of climate evolution due to the interactions of two seasonally distinct precipitation regimes with mountainous landforms in the region.

  17. Regional variations in water quality and relationships to soil and bedrock weathering in the southern Sacramento Valley, California, USA

    USGS Publications Warehouse

    Wanty, R.B.; Goldhaber, M.B.; Morrison, J.M.; Lee, L.

    2009-01-01

    Regional patterns in ground- and surface-water chemistry of the southern Sacramento Valley in California were evaluated using publicly available geochemical data from the US Geological Survey's National Water Information System (NWIS). Within the boundaries of the study area, more than 2300 ground-water analyses and more than 20,000 surface-water analyses were available. Ground-waters from the west side of the Sacramento Valley contain greater concentrations of Na, Ca, Mg, B, Cl and SO4, while the east-side ground-waters contain greater concentrations of silica and K. These differences result from variations in surface-water chemistry as well as from chemical reactions between water and aquifer materials. Sediments that fill the Sacramento Valley were derived from highlands to the west (the Coast Ranges) and east (the Sierra Nevada Mountains), the former having an oceanic provenance and the latter continental. These geologic differences are at least in part responsible for the observed patterns in ground-water chemistry. Thermal springs that are common along the west side of the Sacramento Valley appear to have an effect on surface-water chemistry, which in turn may affect the ground-water chemistry.

  18. A beryllium-10 chronology of late-glacial moraines in the upper Rakaia valley, Southern Alps, New Zealand supports Southern-Hemisphere warming during the Younger Dryas

    NASA Astrophysics Data System (ADS)

    Koffman, Tobias N. B.; Schaefer, Joerg M.; Putnam, Aaron E.; Denton, George H.; Barrell, David J. A.; Rowan, Ann V.; Finkel, Robert C.; Rood, Dylan H.; Schwartz, Roseanne; Plummer, Mitchell A.; Brocklehurst, Simon H.

    2017-08-01

    Interhemispheric differences in the timing of pauses or reversals in the temperature rise at the end of the last ice age can help to clarify the mechanisms that influence glacial terminations. Our beryllium-10 (10Be) surface-exposure chronology for the moraines of the upper Rakaia valley of New Zealand's Southern Alps, combined with glaciological modeling, show that late-glacial temperature change in the atmosphere over the Southern Alps exhibited an Antarctic-like pattern. During the Antarctic Cold Reversal, the upper Rakaia glacier built two well-defined, closely-spaced moraines on Reischek knob at 13,900 ± 120 [1σ; ± 310 yrs when including a 2.1% production-rate (PR) uncertainty] and 13,140 ± 250 (±370) yrs ago, in positions consistent with mean annual temperature approximately 2 °C cooler than modern values. The formation of distinct, widely-spaced moraines at 12,140 ± 200 (±320) and 11,620 ± 160 (±290) yrs ago on Meins Knob, 2 km up-valley from the Reischek knob moraines, indicates that the glacier thinned by ∼250 m during Heinrich Stadial 0 (HS 0, coeval with the Younger Dryas 12,900 to 11,600 yrs ago). The glacier-inferred temperature rise in the upper Rakaia valley during HS 0 was about 1 °C. Because a similar pattern is documented by well-dated glacial geomorphologic records from the Andes of South America, the implication is that this late-glacial atmospheric climate signal extended from 79°S north to at least 36°S, and thus was a major feature of Southern Hemisphere paleoclimate during the last glacial termination.

  19. Warming and glacier recession in the Rakaia valley, Southern Alps of New Zealand, during Heinrich Stadial 1

    SciTech Connect

    Aaron E. Putnam; Joerg M. Schaefe; George H .Denton; DavidJ. A. Barrell; Bjørn G. Andersen; Tobias N.B. Koffman; Ann V. Rowan; Robert C. Finkel; Dylan H. Rood; Roseanne Schwartz; Marcus J. Vandergoes; Mitchell A. Plummer; Simon H. Brocklehurst; Samuel E. Kelley; Kathryn L. Ladig

    2013-11-01

    The termination of the last ice age featured a major reconfiguration of Earth's climate and cryosphere, yet the underlying causes of these massive changes continue to be debated. Documenting the spatial and temporal variations of atmospheric temperature during deglaciation can help discriminate among potential drivers. Here, we present a 10Be surface-exposure chronology and glaciological reconstruction of ice recession following the Last Glacial Maximum (LGM) in the Rakaia valley, Southern Alps of New Zealand. Innermost LGM moraines at Big Ben have an age of 17,840 +/- 240 yrs, whereas ice-marginal moraines or ice-molded bedrock surfaces at distances up-valley from Big Ben of 12.5 km (Lake Coleridge), approximately 25 km (Castle Hill), approximately 28 km (Double Hill), approximately 43 km (Prospect Hill), and approximately 58 km (Reischek knob) have ages of 17,020 +/- 70 yrs, 17,100 +/- 110 yrs, 16,960 +/- 370 yrs, 16,250 +/- 340 yrs, and 15,660 +/- 160 yrs, respectively. These results indicate extensive recession of the Rakaia glacier, which we attribute primarily to the effects of climatic warming. In conjunction with geomorphological maps and a glaciological reconstruction for the Rakaia valley, we use our chronology to infer timing and magnitude of past atmospheric temperature changes. Compared to an overall temperature rise of approximately 4.65?degrees C between the end of the LGM and the start of the Holocene, the glacier recession between approximately 17,840 and approximately 15,660 yrs ago is attributable to a net temperature increase of approximately 4.0?degrees C (from -6.25 to -2.25?degrees C), accounting for approximately 86% of the overall warming. Approximately 3.75?degrees C (approximately 70%) of the warming occurred between approximately 17,840 and approximately 16,250 yrs ago, with a further 0.75?degrees C (approximately 16%) increase between approximately 16,250 and approximately 15,660 yrs ago. A sustained southward shift of the Subtropical

  20. Magnetotelluric evidence for crustal suture zones bounding the southern Great Valley, California

    SciTech Connect

    Park, S.K.; Biasi, G.P. ); Mackie, R.L.; Madden T.R. )

    1991-01-10

    A geoelectric section inferred from a regional magnetotelluric study across the Coast Ranges, the Great Valley, and the Sierra Nevada reveals significant variations in electrical resistivity. Zones of lower resistivity interpreted at depths from 10 km to at least 30 km lie near mapped geologic boundaries between the Coast Ranges and the Great Valley and beneath the eastern side of the Great Valley. The former boundary is inferred by others to separate the subduction complex of the Coast Ranges from the mafic basement of the Great Valley. The lower resistivities are most likely associated with metasediments trapped between the Coast Ranges ophiolite and the former oceanic crust beneath the Great Valley. The latter boundary is problematic, but may be evidence for a deep metasedimentary section trapped between the ophiolites beneath the Great Valley and granitic rocks of the Sierra Nevada. The lack of change in the magnetotelluric phase across the Great Valley indicates that a suture zone marked by lower resistivities is unlikely to be present beneath the valley. However, this does not preclude the existence of a resistive suture zone.

  1. Fluid injection induced seismicity reveals a NE dipping fault in the southeastern sector of the High Agri Valley (southern Italy)

    NASA Astrophysics Data System (ADS)

    Stabile, T. A.; Giocoli, A.; Perrone, A.; Piscitelli, S.; Lapenna, V.

    2014-08-01

    On 2 June 2006 the wastewater produced during the oil and gas field exploitation in High Agri Valley (southern Italy) started to be managed by disposal through pumping the fluids back into the subsurface at the Costa Molina 2 (CM2) injection well, located in the southeastern sector of the valley. The onset of microearthquakes (Ml ≤ 2) after 4 days at about 1.3 km SW of CM2 well suggests fluid injection induced seismicity by the diffusion of pore pressure. Moreover, the space-time evolution of 196 high-resolution relocated events reveals a previously unmapped NE dipping fault. We investigate the physical processes related to the fluid injection induced seismicity and delineate the previously unmapped fault by jointly analyzing seismicity data, geological observations, fluid injection data, the stratigraphic log of the CM2 well, and the electrical resistivity tomography survey carried out in the study area.

  2. Geochemistry of Mesozoic plutons, southern Death Valley region, California: Insights into the origin of Cordilleran interior magmatism

    USGS Publications Warehouse

    Ramo, O.T.; Calzia, J.P.; Kosunen, P.J.

    2002-01-01

    Mesozoic granitoid plutons in the southern Death Valley region of southeastern California reveal substantial compositional and isotopic diversity for Mesozoic magmatism in the southwestern US Cordillera. Jurassic plutons of the region are mainly calc-alkaline mafic granodiorites with ??Ndi of -5 to -16, 87Sr/86Sri of 0.707-0.726, and 206Pb/204Pbi of 17.5-20.0. Cretaceous granitoids of the region are mainly monzogranites with ??Ndi of -6 to -19, 87Sr/86Sri of 0.707-0.723, and 206Pb/204Pbi of 17.4-18.6. The granitoids were generated by mixing of mantle-derived mafic melts and pre-existing crust - some of the Cretaceous plutons represent melting of Paleoproterozoic crust that, in the southern Death Valley region, is exceptionally heterogeneous. A Cretaceous gabbro on the southern flank of the region has an unuasually juvenile composition (??Ndi -3.2, 87Sr/86Sri 0.7060). Geographic position of the Mesozoic plutons and comparison with Cordillera plutonism in the Mojave Desert show that the Precambrian lithosphere (craton margin) in the eastern Mojave Desert region may consists of two crustal blocks separated by a more juvenile terrane.

  3. Carbon and Sulphur Geochemistry of Rift Valley Sediments and Hydrothermal Fluids at the Ultra-Slow Spreading Southern Knipovich Ridge

    NASA Astrophysics Data System (ADS)

    Baumberger, T.; Frueh-Green, G. L.; Pedersen, R. B.; Thorseth, I. H.; Bernasconi, S. M.; Lilley, M. D.

    2008-12-01

    The rift valley of the ultra-slow spreading southern Knipovich Ridge in the Norwegian-Greenland Sea (73°N) is partly buried by a thick sediment cover, as at Middle Valley, Escanaba Trough and Guaymas Basin. These glacial and post-glacial sediments (12000-20000 years) derived from the nearby Bear Island fan likely act as a thermal and hydrogeological boundary to heat and fluid flow and influence hydrothermal fluid compositions. Geochemical studies of the rift valley sediments and the hydrothermal vent fluids of the recently discovered black smoker vent field Loki's Castle provide insights into the influence of the sediment cover on the composition of the hydrothermal fluids at the southern Knipovich Ridge. Here we present an overview of preliminary data on the carbon and sulphur geochemistry of the sedimentary and hydrothermal components at Loki's Castle and compare these with other sedimented and un-sedimented mid-ocean ridge hydrothermal systems. The hydrothermal vent fluids have a pH of 5.5 and are characterized by elevated concentrations of hydrogen, methane, hydrogen sulphide and ammonia, which reflect a strong sedimentary input. Short gravity cores of the rift valley sediments show relatively constant total carbon contents of approximately 1 wt%, but locally reach up to 4 wt%. Varying carbon isotope compositions reflect a mix of marine carbonates with organic carbon. Extracted sediment pore fluids show an increase in alkalinity and dissolved inorganic carbon (DIC) concentrations with increasing burial depth. The corresponding δ13CDIC values show a clear depletion with increasing alkalinity and DIC concentrations. The vent fluid compositions and carbon and sulphur isotope geochemistry provide constraints on redox conditions and thermocatalysis of organic carbon during fluid-sediment interaction, and are distinct from un- sedimented mid-ocean ridge hydrothermal fluids.

  4. Exploring impacts of El Niño Southern Oscillation on Meteorological Forcing within the Glaciated Llanganuco Valley, Peru

    NASA Astrophysics Data System (ADS)

    Covert, J. M.; Hellstrom, R. A.

    2015-12-01

    El Niño Southern Oscillation (ENSO) is known to be the primary modulator of inter-annual weather patterns in the Andes, but its impact in the Cordillera Blanca (White Range) is not fully understood. In 2004 an autonomous sensor network (ASN) was installed in the Llanganuco Valley in the Cordillera Blanca, Peru consisting of two automatic weather stations (AWS) located at the base and upper ridge of the valley connected by four air temperature/humidity micro-loggers at equal elevation intervals. The ASN permits high resolution evaluations of the micro-scale meteorology within the valley. Twenty-four hour composites and monthly averages of wind, solar insolation, air temperature profiles, and precipitation obtained from the ASN were analyzed for the historical wet and dry seasons between the years of 2005 and 2015. The evidence suggests that teleconnections exist between eastern equatorial Pacific Ocean sea surface temperatures and meteorological forcing within the Valley. Comparisons between the two AWS units reveal similar ENSO impacts during the wet season that are not replicated in the dry season. We found that warm and cold ENSO create anomalies that appear unique to this region of the outer Tropics. Warm ENSO phases promote wetter than normal dry seasons and dryer than normal wet seasons and visa versa for cold phases of ENSO. Air temperature is strongly positively correlated to warm ENSO phases during the wet season and depends on elevation during the dry season. Insolation is negatively correlated to warm ENSO phases at higher elevations with weak positive correlation at lower elevations. We attribute observed seasonality, in part, to interactions between channeling of synoptic flow and thermally driven winds. Although the sporadic availability of data prevents definitive conclusions at this time, recent improvements in the ASN infrastructure will facilitate deeper understanding of ENSO impacts on meteorological forcing within pro-glacial valleys of the

  5. Chronology and provenance of alluvial fills in the dry valley environment of the lower Molopo River, southern Kalahari

    NASA Astrophysics Data System (ADS)

    Ramisch, Arne; Bens, Oliver; Eden, Marie; Hürkamp, Kerstin; Schwindt, Daniel; Völkel, Jörg

    2016-04-01

    The dry valleys of the Molopo-Kuruman and the Nossob-Auob system form the largest drainage basin of the southern Kalahari, with a total drainage area of over 100.000 km². The South-Kalahari drainage system is connected to the perennial Orange River by the lower Molopo valley which is therefore the only potential fluvial outlet for sediments originating from the southern Kalahari. Despite its key geomorphological position, little is known about Late Quaternary landscape dynamic in the lower Molopo section. To estimate the timing of fluvial sedimentation phases near the Molopo-Orange confluence, we sampled alluvial fills within the narrow trench of the Molopo canyon. The chronology was established using a total of 15 Optical Stimulated Luminescence (OSL) samples from key profiles within the canyon. The results suggest that landscape development was dominated by two phases of valley infill during a) the Mid Holocene and b) the Late Holocene. To gain insight into sediment dynamics during these intervals, we carried out a provenance analysis on the fine fraction (< 2 mm) of fluvial sediments. Sediment source areas were estimated by analyzing the elemental and mineralogical composition of 93 tributaries and 32 dune deposits throughout the reaches of the lower Molopo via X-ray fluorescence (XRF) and X-ray diffraction analysis (XRD). The appliance of a fuzzy cluster algorithm on the elemental and mineralogical composition of reference samples revealed three major sediment source areas: i) The Molopo canyon, ii) fluvial source areas north of the canyon and iii) eolian sands covering the recent lower Molopo valley in its upper reaches. A similarity analysis between fluvial sediments of the Molopo canyon to the previously identified source areas suggests that alluvial fills mainly originate from the canyon itself, suggesting short-distance sediment mobilization as the driving mechanism behind aggradation. Thereby, both Holocene intervals differ in the mean distance of

  6. Stratigraphical framework of basaltic lavas in Torres Syncline main valley, southern Parana-Etendeka Volcanic Province

    NASA Astrophysics Data System (ADS)

    Rossetti, Lucas M.; Lima, Evandro F.; Waichel, Breno L.; Scherer, Claiton M.; Barreto, Carla J.

    2014-12-01

    The Paraná-Etendeka Volcanic Province records the volcanism of the Early Cretaceous that precedes the fragmentation of the South-Gondwana supercontinent. Traditionally, investigations of these rocks prioritized the acquisition of geochemical and isotopic data, considering the volcanic stack as a monotonous succession of tabular flows. Torres Syncline is a tectonic structure located in southern Brazil and where the Parana-Etendeka basalts are well preserved. This work provides a detailed analysis of lithofacies and facies architecture, integrated to petrographic and geochemical data. We identified seven distinct lithofacies grouped into four facies associations related to different flow morphologies. The basaltic lava flows in the area can be divided into two contrasting units: Unit I - pahoehoe flow fields; and Unit II - simple rubbly flows. The first unit is build up by innumerous pahoehoe lava flows that cover the sandstones of Botucatu Formation. These flows occur as sheet pahoehoe, compound pahoehoe, and ponded lavas morphologies. Compound lavas are olivine-phyric basalts with intergranular pyroxenes. In ponded lavas and cores of sheet flows coarse plagioclase-phyric basalts are common. The first pahoehoe lavas are more primitive with higher contents of MgO. The emplacement of compound pahoehoe flows is related to low volume eruptions, while sheet lavas were emplaced during sustained eruptions. In contrast, Unit II is formed by thick simple rubbly lavas, characterized by a massive core and a brecciated/rubbly top. Petrographically these flows are characterized by plagioclase-phyric to aphyric basalts with high density of plagioclase crystals in the matrix. Chemically they are more differentiated lavas, and the emplacement is related to sustained high effusion rate eruptions. Both units are low TiO2 and have geochemical characteristics of Gramado magma type. The Torres Syncline main valley has a similar evolution when compared to other Large Igneous Provinces

  7. Paleoseismology study of Luyeh fault, the west branch of southern-most Longitudinal Valley fault

    NASA Astrophysics Data System (ADS)

    Chi, C.; Chen, W.

    2010-12-01

    The Longitudinal Valley fault (LVF) is the active suture between Eurasian plate and Philippine Sea plate. This study we focus on the southern-most segment of LVF, where it branches into two parallel imbricated faults, the Luyeh fault (LYF) in the west and Lichi fault (LCF) in the east. A trench for paleoseismologic research has been excavated across a 3 m high monoclino-scarp near the north end of the LYF. All the layers in the trench are folded and are west dipping with a tendency of steepening downward. Based on the onlapping structures, dip angle change, and fault cutting relation, we resolve 3 paleoearthquake events. The timing of these events which are in about 4300 yr BP (E3), 2200 yr BP (E2), and after 2200 yr BP (E1) are constrained by 14C dating of the sedimentary layers. The vertical uplift restored from the unconformities are 2.24-2.47 m (E3), 1.02-1.36 m (E2), and 2.92-3.07 m (E1) respectively. Long-term uplift rate is about 1.5 mm/yr and the slip rate is about 4.5 mm/yr calculated by fault dip angle 20°. Two boreholes in the south of the trench were drilled. The mud deposits dated as 13060-12840 cal yr BP in MB-01 core has sheared, these shear zone can be correlated to the surface lineament (F1) extend to the trench site. This suggests the fault has activated after 13000 yr BP. The shear zone in 186.0-187.0 m of MB-02 core can be extrapolated to the scarp in the surface. This branch (F2) should be less or no more active because it doesn’t have any imprint on the terrace surface in the north. The unusual thick mud deposit in MB-01 core is dated as 18510-17690 cal yr BP in 69.6 m depth. This means a sudden depositional environment change from fluvial to lacustrine environment before this age. We infer the F2 branch was active and uplifted the terrace at that time. Therefore it can serve as a barrier that dammed the downstream side of the stream and formed a lake. The recurrence time deduced from E3 and E2 is about 2100 yr. If this is almost the same

  8. The Salton Seismic Imaging Project: Tomographic characterization of a sediment-filled rift valley and adjacent ranges, southern California

    NASA Astrophysics Data System (ADS)

    Davenport, K.; Hole, J. A.; Stock, J. M.; Fuis, G. S.; Carrick, E.; Tikoff, B.

    2011-12-01

    The Salton Trough in Southern California represents the northernmost rift of the Gulf of California extensional system. Relative motion between the Pacific and North American plates is accommodated by continental rifting in step-over zones between the San Andreas, Imperial, and Cerro Prieto transform faults. Rapid sedimentation from the Colorado River has isolated the trough from the southern portion of the Gulf of California, progressively filling the subsiding rift basin. Based on data from previous seismic surveys, the pre-existing continent has ruptured completely, and a new ~22 km thick crust has been created entirely by sedimentation overlying rift-related magmatism. The MARGINS, EarthScope, and USGS-funded Salton Seismic Imaging Project (SSIP) was designed to investigate the nature of this new crust, the ongoing process of continental rifting, and associated earthquake hazards. SSIP, acquired in March 2011, comprises 7 lines of onshore seismic refraction / wide-angle reflection data, 2 lines of refraction / reflection data in the Salton Sea, and a line of broadband stations. This presentation focuses on the refraction / wide-angle reflection line across the Imperial Valley, extending ~220 km across California from Otay Mesa, near Tijuana, to the Colorado River. The data from this line includes seventeen 100-160 kg explosive shots and receivers at 100 m spacing across the Imperial Valley to constrain the structure of the Salton Trough rift basin, including the Imperial Fault. Eight larger shots (600-920 kg) at 20-35 km spacing and receivers at 200-500 m spacing extend the line across the Peninsular Ranges and the Chocolate Mountains. These data will contrast the structure of the rift to that of the surrounding crust and provide constraints on whole-crust and uppermost mantle structure. Preliminary work has included tomographic inversion of first-arrival travel times across the Valley, emphasizing a minimum-structure approach to create a velocity model of the

  9. Is it working? A look at the changing nutrient practices in Oregon's Southern Willamette Valley Groundwater Management Area

    NASA Astrophysics Data System (ADS)

    Pearlstein, S.; Compton, J.; Eldridge, A.; Henning, A.; Selker, J. S.; Brooks, J. R.; Schmitz, D.

    2016-12-01

    Groundwater nitrate contamination affects thousands of households in the southern Willamette Valley and many more across the Pacific Northwest. The southern Willamette Valley Groundwater Management Area (SWV GWMA) was established in 2004 due to nitrate levels in the groundwater exceeding the human health standard of 10 mg nitrate-N L-1. Much of the nitrogen inputs to the GWMA comes from agricultural nitrogen use, and thus efforts to reduce N inputs to groundwater are focused upon improving N management. Previous work in the 1990s in the Willamette Valley by researchers at Oregon State University determined the importance of cover crops and irrigation practices and made recommendations to the local farm community for reducing nitrogen (N) leaching. We are currently re-sampling many of the same fields studied by OSU to examine the influence of current crops and nutrient management practices on nitrate leaching below the rooting zone. This study represents important crops currently grown in the GWMA and includes four grass fields, three vegetable row-crop fields, two peppermint and wheat fields, and one each of hazelnuts and blueberries. New nutrient management practices include slow release fertilizers and precision agriculture approaches in some of the fields. Results from the first two years of sampling show nitrate leaching is lower in some crops like row crops grown for seed and higher in others like perennial rye grass seed when compared to the 1990s data. We will use field-level N input-output balances in order to determine the N use efficiency and compare this across crops and over time. The goal of this project is to provide information and tools that will help farmers, managers and conservation groups quantify the water quality benefits of management practices they are conducting or funding.

  10. Mapping deep aquifer salinity trends in the southern San Joaquin Valley using borehole geophysical data constrained by chemical analyses

    NASA Astrophysics Data System (ADS)

    Gillespie, J.; Shimabukuro, D.; Stephens, M.; Chang, W. H.; Ball, L. B.; Everett, R.; Metzger, L.; Landon, M. K.

    2016-12-01

    The California State Water Resources Control Board and the California Division of Oil, Gas and Geothermal Resources are collaborating with the U.S. Geological Survey to map groundwater resources near oil fields and to assess potential interactions between oil and gas development and groundwater resources. Groundwater resources having salinity less than 10,000 mg/L total dissolved solids may be classified as Underground Sources of Drinking Water (USDW) and subject to protection under the federal Safe Drinking Water Act. In this study, we use information from oil well borehole geophysical logs, oilfield produced water and groundwater chemistry data, and three-dimensional geologic surfaces to map the spatial distribution of salinity in aquifers near oil fields. Salinity in the southern San Joaquin Valley is controlled primarily by depth and location. The base of protected waters occurs at very shallow depths, often < 300 meters, in the western part of the valley where aquifer recharge is low in the rain shadow of the Coast Ranges. The base of protected water is much deeper, often >1,500 meters, in the eastern part of the San Joaquin Valley where higher runoff from the western slopes of the Sierra Nevada provide relatively abundant aquifer recharge. Stratigraphy acts as a secondary control on salinity within these broader areas. Formations deposited in non-marine environments are generally fresher than marine deposits. Layers isolated vertically between confining beds and cut off from recharge sources may be more saline than underlying aquifers that outcrop in upland areas on the edge of the valley with more direct connection to regional recharge areas. The role of faulting is more ambiguous. In some areas, abrupt changes in salinity may be fault controlled but, more commonly, the faults serve as traps separating oil-bearing strata that are exempt from USDW regulations, from water-bearing strata that are not exempt.

  11. Interseismic Strain Accumulation in the Imperial Valley and Implications for Triggering of Large Earthquakes in Southern California

    NASA Astrophysics Data System (ADS)

    Crowell, B. W.; Bock, Y.; Sandwell, D. T.

    2009-12-01

    From February, 2008 to March, 2009, we performed three rapid-static Global Positioning System (GPS) surveys of 115 geodetic monuments stretching from the United States-Mexico border into the Coachella Valley using the method of instantaneous positioning. The monuments are located in key areas near the Imperial, Superstition Hills, San Jacinto, San Andreas and Brawley Faults with nominal baselines generally less than 10 km. We perform a bicubic spline interpolation on the crustal motion vectors from the campaign measurements and 1005 continuous GPS monuments in western North America and solve for the velocity gradient tensor to look at the maximum shear strain, dilatation and rotation rates in the Imperial Valley. We then compare our computed strain field to that computed using the Southern California Earthquake Center Crustal Motion Map 3.0, which extends through 2003 and includes 840 measurements. We show that there is an interseismic strain transient that corresponds to an increase in the maximum shear strain rate of 0.7 μstrain/yr near Obsidian Buttes since 2003 along a fault referred to as the Obsidian Buttes Fault (OBF). A strong subsidence signal of 27 mm/yr and a left-lateral increase of 10 mm/yr are centered along the OBF. Changes in the dilatation and rotation rates confirm the increase in left-lateral motion, as well as infer a strong increase in spreading rate in the southern Salton Sea. The increase in spreading rate has caused an accelerated slip rate along the southern San Andreas near Durmid Hill as evidenced by continuous GPS, which has the potential for earthquake triggering.

  12. Slip Rates, Recurrence Intervals and Earthquake Event Magnitudes for the southern Black Mountains Fault Zone, southern Death Valley, California

    NASA Astrophysics Data System (ADS)

    Fronterhouse Sohn, M.; Knott, J. R.; Bowman, D. D.

    2005-12-01

    The normal-oblique Black Mountain Fault zone (BMFZ) is part of the Death Valley fault system. Strong ground-motion generated by earthquakes on the BMFZ poses a serious threat to the Las Vegas, NV area (pop. ~1,428,690), the Death Valley National Park (max. pop. ~20,000) and Pahrump, NV (pop. 30,000). Fault scarps offset Holocene alluvial-fan deposits along most of the 80-km length of the BMFZ. However, slip rates, recurrence intervals, and event magnitudes for the BMFZ are poorly constrained due to a lack of age control. Also, Holocene scarp heights along the BMFZ range from <1 m to >6 m suggesting that geomorphic sections have different earthquake histories. Along the southernmost section, the BMFZ steps basinward preserving three post-late Pleistocene fault scarps. Surveys completed with a total station theodolite show scarp heights of 5.5, 5.0 and 2 meters offsetting the late Pleistocene, early to middle Holocene, to middle-late Holocene surfaces, respectively. Regression plots of vertical offset versus maximum scarp angle suggest event ages of <10 - 2 ka with a post-late Pleistocene slip rate of 0.1mm/yr to 0.3 mm/yr and recurrence of <3300 years/event. Regression equations for the estimated geomorphically constrained rupture length of the southernmost section and surveyed event displacements provides estimated moment magnitudes (Mw) between 6.6 and 7.3 for the BMFZ.

  13. Contractional Strain Related to Interference of Intersecting Sets of Strike-slip Faults in the Southern Death Valley Region, California

    NASA Astrophysics Data System (ADS)

    Menges, C. M.; Pavlis, T. L.; McMackin, M. R.; Serpa, L.

    2006-12-01

    Structural and geomorphic data reveal complex neotectonic deformation(Pliocene-Quaternary, post 3-4 Ma)derived in part from interactions among intersecting sets of strike-slip faults in the southern Death Valley area on the eastern margin of the Eastern California Shear Zone. A distinct 40-km-wide domain of strike-slip faulting and associated contractional strain is bounded on the north by the southern end of the Panamint and Death Valley extensional terrane and on the south by the eastern Garlock fault (EGF). The dominant regional structures are (a) two NW-trending dextral-slip faults—the southern Death Valley fault (SDVF) and southern Panamint Valley fault (SPVF), and (b) three E- to NE-oriented sinistral-slip faults. This latter set includes the EGF, an associated splay of the Owl Lake fault (OLF) and a diffuse fault zone associated with discontinuous surface rupture in upper and central Wingate Wash valley (WWF). The strike-slip faults intersect with one another in a complex interference pattern that produces on-fault zones of transpressive deformation. These faults, moreover, are embedded within widespread areas of off-fault contractional strain in the intervening crustal blocks. Specifically, secondary on-fault transpressive deformation occurs along the majority of the EGF and SDVF and sections of the OLF and SPVF. This transpression is manifested as commonly asymmetric flower structures that produce domal to elongate zones of uplifted topography along the fault trace. Surface deformation within the flower structure appears partitioned between (a)translation along strike-slip faults in the dissected core of the uplifts and (b) contraction and uplift accommodated on near-surface blind thrusts below fault-propagation folds on the flanks of the structure. Where two or more large strike-slip faults intersect one another, one or more of the structures typically merges with or is truncated against one primary though-going structure. The geometry and slip-sense of

  14. Outlook for Mississippi Alluvial Valley forests: a subregional report from the Southern Forest Futures Project

    Treesearch

    Emile S. Gardiner

    2015-01-01

    The Mississippi Alluvial Valley, which can be broadly subdivided into the Holocene Deposits section and the Deltaic Plain section, is a 24.9-million-acre area generally approximating the alluvial floodplain and delta of the lower Mississippi River. Its robust agricultural economy is maintained by a largely rural population, and recreational resources draw high...

  15. Epidemiologic and environmental risk factors of rift valley fever in southern Africa from 2008 to 2011

    USDA-ARS?s Scientific Manuscript database

    BACKGROUND: Rift Valley fever outbreaks have been associated with periods of widespread and above average rainfall over several months which allows for the virus infected mosquito vector populations to emerge and propagate. This has provided basis to develop complex models based on environmental fa...

  16. Geochemical and Isotopic Interpretations of Groundwater Flow in the Oasis Valley Flow System, Southern Nevada

    SciTech Connect

    J.M. Thomas; F.C. Benedict, Jr.; T.P. Rose; R.L. Hershey; J.B. Paces; Z.E. Peterman; I.M. Farnham; K.H. Johannesson; A.K. Singh; K.J. Stetzenbach; G.B. Hudson; J.M. Kenneally; G.F. Eaton; D.K. Smith

    2003-01-08

    This report summarizes the findings of a geochemical investigation of the Pahute Mesa-Oasis Valley groundwater flow system in southwestern Nevada. It is intended to provide geochemical data and interpretations in support of flow and contaminant transport modeling for the Western and Central Pahute Mesa Corrective Action Units.

  17. Early and abrupt retreat of the Laurentide Ice Sheet margin from the Mackenzie River valley, southern Northwest Territories

    NASA Astrophysics Data System (ADS)

    Margold, Martin; Froese, Duane G.; Gosse, John C.; Yang, Guang; McKenna, Jillian; Hidy, Alan J.

    2017-04-01

    The detachment of the Laurentide Ice Sheet margin from the Canadian Cordillera opened the present-day drainage route of the Mackenzie River to the Arctic Ocean and an ice-free corridor that allowed for migration of species between Beringia and the mid-latitudes of North America. The existing ice-margin chronology depicts the southern reach of the Mackenzie River between 61 and 63° N as glaciated until about 13 ka, representing the last portion of the Laurentide Ice Sheet margin abutting the eastern foot of the Cordillera. A substantial retreat of the ice sheet margin in this region has been suggested to have occurred during the subsequent Younger Dryas cold period, despite the fact that in many other regions ice masses stabilised or even re-grew at this time. However, until now, deglacial chronometry for this region and the western LIS margin is sparse and consists mostly of minimum-limiting macrofossil and bulk C-14 ages from organics materials overlying glacial sediment. With the aim to bring new data on the deglaciation history of the Mackenzie River valley, we collected samples for Be-10 exposure dating from glacial erratic boulders in the southern Franklin Mountains that bound the Mackenzie River valley from the east. The sampling elevations ranged between 1480 and 800 m a.s.l., however, the measured ages show only a weak correlation with elevation. Instead, 10 out of 12 measured samples cluster tightly around 15 ka, with the remaining two samples likely containing Be-10 inherited from previous periods of exposure. Our results thus indicate a pre-Younger Dryas rapid down-wasting of the ice sheet surface, which we infer was accompanied by an ice margin retreat to the southeast. The southern reach of the Mackenzie River valley at the eastern foot of the Cordillera was, according to our results, ice free shortly after 15 ka, with the prospect that the ice-free corridor might have opened significantly earlier than hitherto anticipated. Further research is

  18. A New Strategy for the Electromagnetic Monitoring of Seismic Areas: the Case-Study of Agri Valley (Southern Italy).

    NASA Astrophysics Data System (ADS)

    Lapenna, V.; Balasco, M.; Giocoli, A.; Piscitelli, S.; Rizzo, E.; Romano, G.; Siniscalchi, A.; Telesca, L.

    2008-12-01

    The Agri valley is one of the most active areas of Southern Apennine chain that was hidden by destructive events in historical and recent periods (i.e. the 1857 Great Neapolitan earthquake). The geological environment is extremely complex and the location of the main faults are still debated. The Agriu valley is a N- W elongated basin filled by quaternary deposits covering the pre-quaternary rock of the Apennine chain. The area is characterised by a very low man-made electromagnetic noise and it represents an ideal "outdoor laboratory" to test new strategies for geophysical monitoring of active faults. In this work we present a novel approach based on the integration of Deep Electrical Resistivity Tomography (DERT), Self-Potential (SP) and Magnetotelluric (MT) time-continuous measurements. The basic idea underlying this approach is to jointly analyse and modelling the electrical signals, observed on earth-surface, and the time-dependent changes of subsurface resistivity patterns. We are firmly convinced that any conclusions about the relationship between anomalous electrical signals and earthquake activity cannot be achieved without a good knowledge of subsurface resistivity structures and an accurate localisation of the electrical sources. In our work DERT has been applied for illuminating in-depth the geological structures and giving a contribute to better define the thickness and the shape of alluvial deposits covering the pre- quaternary bedrock of Agri valley. SP surveying and time-continuous monitoring have been carried to study electrokinetic effects due to groundwater patterns and to identify possible fingerprints of fluid migration phenomena. New SP stations with sensors in boreholes (200m) have been installed. MT time-continuous soundings have been performed to analyse the time-dependent changes in deep resistivity patterns. All data measured in the study area have been processed and filtered using robust statistical methodologies (DFA, wavelet, multi

  19. Seismic calibration shots conducted in 2009 in the Imperial Valley, southern California, for the Salton Seismic Imaging Project (SSIP)

    USGS Publications Warehouse

    Murphy, Janice; Goldman, Mark; Fuis, Gary; Rymer, Michael; Sickler, Robert; Miller, Summer; Butcher, Lesley; Ricketts, Jason; Criley, Coyn; Stock, Joann; Hole, John; Chavez, Greg

    2011-01-01

    Rupture of the southern section of the San Andreas Fault, from the Coachella Valley to the Mojave Desert, is believed to be the greatest natural hazard facing California in the near future. With an estimated magnitude between 7.2 and 8.1, such an event would result in violent shaking, loss of life, and disruption of lifelines (freeways, aqueducts, power, petroleum, and communication lines) that would bring much of southern California to a standstill. As part of the Nation's efforts to prevent a catastrophe of this magnitude, a number of projects are underway to increase our knowledge of Earth processes in the area and to mitigate the effects of such an event. One such project is the Salton Seismic Imaging Project (SSIP), which is a collaborative venture between the United States Geological Survey (USGS), California Institute of Technology (Caltech), and Virginia Polytechnic Institute and State University (Virginia Tech). This project will generate and record seismic waves that travel through the crust and upper mantle of the Salton Trough. With these data, we will construct seismic images of the subsurface, both reflection and tomographic images. These images will contribute to the earthquake-hazard assessment in southern California by helping to constrain fault locations, sedimentary basin thickness and geometry, and sedimentary seismic velocity distributions. Data acquisition is currently scheduled for winter and spring of 2011. The design and goals of SSIP resemble those of the Los Angeles Region Seismic Experiment (LARSE) of the 1990's. LARSE focused on examining the San Andreas Fault system and associated thrust-fault systems of the Transverse Ranges. LARSE was successful in constraining the geometry of the San Andreas Fault at depth and in relating this geometry to mid-crustal, flower-structure-like decollements in the Transverse Ranges that splay upward into the network of hazardous thrust faults that caused the 1971 M 6.7 San Fernando and 1987 M 5

  20. Inventory of San Joaquin kit fox on BLM lands in southern and southwestern San Joaquin Valley. Final report

    SciTech Connect

    O'Farrell, T.P.; Kato, T.; McCue, P.; Sauls, M.L.

    1980-08-01

    The objectives of this study were to provide the Bureau of Land Management, Bakersfield District, with information on the distribution of the San Joaquin kit fox, an endangered species, on public lands in the southern and southwestern San Joaquin Valley of California, and to develop information essential for designating kit fox critical habitats on lands under their jurisdiction as outlined by the Endangered Species Act and its amendments. A total of 31,860 acres of BLM lands were surveyed using line transects at a density of 8 per linear mile. Observations were recorded on: (1) kit fox dens, tracks, scats, and remains of their prey; (2) vegetation associations; (3) topography; (4) evidence of human activities; (5) species composition and abundance of wildlife seen, especially lagomorphs; (6) presence of Eriogonum gossypinum, a plant of special interest; and (7) presence of the blunt-nosed leopard lizard, another endangered species.

  1. Factors motivating Latino college students to pursue STEM degrees on CSU campuses in the southern San Joaquin Valley

    NASA Astrophysics Data System (ADS)

    Ramirez, Gabriel

    The purpose of this study was to determine what factors were motivating Latino/a students in the southern San Joaquin Valley to pursue STEM degrees and whether these factors were specific to the Latino/a culture. A 12-question survey was administered to STEM majors at California State University, Bakersfield and California State University, Fresno and interviews were conducted with those survey respondents who agreed to be part of the process. The results of the survey suggested that factors such as STEM subject matter, STEM career knowledge, the possibility of a high paying salary, high school STEM grades, and family influence were significant in motivating Latino/a students to pursue STEM degrees. The results of the Chi Square Test suggested the Latino/a students' responses about college STEM degree granting statistics, the possibility of a high salary, and the effects of setbacks were significantly different to those of their non-Latino/a counterparts.

  2. Geologic Utility of LANSDAT-4 TM Data. [Death Valley, California and the Silver Bell area of southern Arizona

    NASA Technical Reports Server (NTRS)

    Abrams, M.; Kahle, A. B.; Gillespie, A.; Conel, J.; Lang, H.

    1985-01-01

    The performance of the TM vis-a-vis various geological applications was quantified by analyzing: (1) the geological utility of the data with respect to the increased spatial resolution and number of bands (compared to the MSS); (2) the geometric accuracy; (3) the radiometric performance of the TM scanner. Preliminary analyses were performed on TM scenes: over Death Valley, California, and over southern Arizona. Both scenes were acquired in CCT-PT format, where the data were geometrically and radiometrically corrected. Overall, the TM data appears to contain a marked increase in geologically useful information; however, a number of instrumental or processing artifacts may well limit the ability of the geologist to fully extract this information.

  3. Topographic growth around the Orange River valley, southern Africa: A Cenozoic record of crustal deformation and climatic change

    NASA Astrophysics Data System (ADS)

    Dauteuil, Olivier; Bessin, Paul; Guillocheau, François

    2015-03-01

    We reconstruct the history of topographic growth in southern Africa on both sides of the Orange River valley from an integrated analysis of erosion surfaces, crustal deformation and climate change. First, we propose an inventory of erosion surfaces observed in the study area and classify them according to their most likely formative process, i.e. chemical weathering or mechanical erosion. Among the various land units observed we define a new class of landform: the pedivalley, which corresponds to a wide valley with a flat erosional floor. In the Orange River valley, we mapped three low-relief erosion surfaces, each bevelling a variety of lithologies. The oldest and most elevated is (1) a stripped etchplain evolving laterally into (2) a stepped pediplain bearing residual inselbergs; (3) a younger pediplain later formed in response to a more recent event of crustal deformation. These are all Cenozoic landforms: the etchplain is associated with a late Palaeocene to middle Eocene weathering event, and the two pediplains are older than the middle Miocene alluvial terraces of the Orange River. Landscape evolution was first driven by slow uplift (10 m/Ma), followed by a second interval of uplift involving a cumulative magnitude of at least 200 m. This event shaped the transition between the two pediplains and modified the drainage pattern. A final phase of uplift (magnitude: 60 m) occurred after the Middle Miocene and drove the incision of the lower terraces of the Orange River. Climate exerted a major control over the denudation process, and involved very humid conditions responsible for lateritic weathering, followed by more arid conditions, which promoted the formation of pedivalleys. Collectively, these produce pediplains.

  4. Geophysical Studies in the Vicinity of the Warner Mountains and Surprise Valley, Northeast California, Northwest Nevada, and Southern Oregon

    USGS Publications Warehouse

    Ponce, David A.; Glen, Jonathan M.G.; Egger, Anne E.; Bouligand, Claire; Watt, Janet T.; Morin, Robert L.

    2009-01-01

    From May 2006 to August 2007, the U.S. Geological Survey (USGS) collected 793 gravity stations, about 102 line-kilometers of truck-towed and ground magnetometer data, and about 325 physical-property measurements in northeastern California, northwestern Nevada, and southern Oregon. Gravity, magnetic, and physical-property data were collected to study regional crustal structures and geology as an aid to understanding the geologic framework of the Surprise Valley geothermal area and, in general, geothermal systems throughout the Great Basin. The Warner Mountains and Surprise Valley mark the transition from the extended Basin and Range province to the unextended Modoc Plateau. This transition zone, in the northwestern corner of the Basin and Range, is relatively diffuse compared to other, more distinct boundaries, such as the Wasatch front in Utah and the eastern Sierran range front. In addition, this transition zone is the site of a geothermal system with potential for development, and previous studies have revealed a complex structural setting consisting of several obliquely oriented fault sets. As a result, this region has been the subject of several recent geological and geophysical investigations. The gravity and magnetic data presented here support and supplement those studies, and although the study area is composed predominantly of Tertiary volcanic rocks of the Modoc Plateau rocks, the physical properties of these and others rocks create a distinguishable pattern of gravity and magnetic anomalies that can be used to infer subsurface geologic structure.

  5. Geologic map of the southern Funeral Mountains including nearby groundwater discharge sites in Death Valley National Park, California and Nevada

    USGS Publications Warehouse

    Fridrich, C.J.; Thompson, R.A.; Slate, J.L.; Berry, M.E.; Machette, M.N.

    2012-01-01

    This 1:50,000-scale geologic map covers the southern part of the Funeral Mountains, and adjoining parts of four structural basins—Furnace Creek, Amargosa Valley, Opera House, and central Death Valley—in California and Nevada. It extends over three full 7.5-minute quadrangles, and parts of eleven others—an area of about 1,000 square kilometers (km2). The boundaries of this map were drawn to include all of the known proximal hydrogeologic features that may affect the flow of groundwater that discharges from springs of the Furnace Creek basin, in the west-central part of the map. These springs provide the main potable water supply for Death Valley National Park. Major hydrogeologic features shown on this map include: (1) springs of the Furnace Creek basin, (2) a large Pleistocene groundwater discharge mound in the northeastern part of the map, (3) the exposed extent of limestones and dolomites that constitute the Paleozoic carbonate aquifer, and (4) the exposed extent of the alluvial conglomerates that constitute the Funeral Formation aquifer.

  6. Oil/gas pre-treatment plants and air quality hazards: PM1 measurements in Agri Valley (southern Italy)

    NASA Astrophysics Data System (ADS)

    Trippetta, S.; Caggiano, R.; Sabia, S.

    2014-04-01

    A PM1 (i.e., aerosol particles with aerodynamic diameter less 1.0 μm) short term monitoring campaign was carried out in Agri Valley (southern Italy) in September 2012. This area is of international concern since it houses the largest European on-shore reservoir and the largest oil/gas pre-treatment plant (i.e., Centro Olio Val d'Agri - COVA) within an anthropized context. PM1 measurements were performed in Viggiano, the nearest town to the COVA plant and one of the most populated town of the Agri Valley. During the study period, the PM1 daily concentrations ranged from 1.2 to 8.4 μg m-3 with a mean value of 4.6 μg m-3. Regarding the PM1 chemical composition, it can be observed that S and typical crustal elements were the most abundant constituents of the PM1 collected. By applying the Principal Component Analysis, it was pointed out that crustal soil, biomass and wood burning, secondary atmospheric reactions involving COVA plant emissions and local soil particles, and traffic were the main sources contributing to the PM1 measured in the area under study. Moreover, a possible contribution of the long-range transport of African dust was observed.

  7. Geomorphic and sedimentary responses of the Bull Creek Valley (Southern High Plains, USA) to Pleistocene and Holocene environmental change

    NASA Astrophysics Data System (ADS)

    Arauza, Hanna M.; Simms, Alexander R.; Bement, Leland C.; Carter, Brian J.; Conley, Travis; Woldergauy, Ammanuel; Johnson, William C.; Jaiswal, Priyank

    2016-01-01

    Fluvial geomorphology and stratigraphy often reflect past environmental and climate conditions. This study examines the response of Bull Creek, a small ephemeral creek in the Oklahoma panhandle, to environmental conditions through the late Pleistocene and Holocene. Fluvial terraces were mapped and their stratigraphy and sedimentology documented throughout the course of the main valley. Based on their elevations, terraces were broadly grouped into a late-Pleistocene fill terrace (T3) and two Holocene fill-cut terrace sets (T2 and T1). Terrace systems are marked by similar stratigraphies recording the general environmental conditions of the time. Sedimentary sequences preserved in terrace fills record the transition from a perennial fluvial system during the late glacial period and the Younger Dryas to a semiarid environment dominated by loess accumulation and punctuated by flood events during the middle to late Holocene. The highest rates of aeolian accumulation within the valley occurred during the early to middle Holocene. Our data provide significant new information regarding the late-Pleistocene and Holocene environmental history for this region, located between the well-studied Southern and Central High Plains of North America.

  8. The relationship between the summer precipitation in the Yangtze River valley and the boreal spring Southern Hemisphere annular mode

    NASA Astrophysics Data System (ADS)

    Nan, Sulan; Li, Jianping

    2003-12-01

    The relationship between the boreal spring (April-May) Southern Hemisphere annular mode (SAM) and the following summer (June-August) precipitation in China for the period of 1951-2001 is examined statistically in this study. There is a significantly positive correlation between the boreal spring SAM index (SAMI) and the following summer rainfall in the middle and lower reaches of the Yangtze River. The summer large-scale atmospheric circulation anomalies over East Asia are also related to the boreal spring SAMI events. A strong SAM in boreal spring is followed by a weakened East Asian summer monsoon, a strengthened and westward expanded western Pacific subtropical high (WPSH), as well as increased ascending vertical velocity, specific humidity and water vapor flux convergence. These situations provide necessary circulation and water vapor conditions for increasing the summer precipitation in the middle and lower reaches of the Yangtze River valley, and vice versa. The boreal spring SAM variation provides a potential valuable signal for predicting the summertime precipitation in the middle and lower reaches of the Yangtze River valley.

  9. Thrust faults of southern Diamond Mountains, central Nevada: Implications for hydrocarbons in Diamond Valley and at Yucca Mountain

    SciTech Connect

    French, D.E.

    1993-04-01

    Overmature Mississippian hydrocarbon source rocks in the southern Diamond Mountains have been interpreted to be a klippe overlying less mature source rocks and represented as an analogy to similar conditions near Yucca Mountain (Chamberlain, 1991). Geologic evidence indicates an alternative interpretation. Paleogeologic mapping indicates the presence of a thrust fault, referred to here as the Moritz Nager Thrust Fault, with Devonian rocks emplaced over Permian to Mississippian strata folded into an upright to overturned syncline, and that the overmature rocks of the Diamond Mountains are in the footwall of this thrust. The upper plate has been eroded from most of the Diamond Mountains but remnants are present at the head of Moritz Nager Canyon and at Sentinel Mountain. Devonian rocks of the upper plate comprised the earliest landslide megabreccia. Later, megabreccias of Pennsylvanian and Permian rocks of the overturned syncline of the lower plate were deposited. By this interpretation the maturity of lower-plate source rocks in the southern Diamond Mountains, which have been increased by tectonic burial, is not indicative of conditions in Diamond Valley, adjacent to the west, where upper-plate source rocks might be present in generating conditions. The interpretation that overmature source rocks of the Diamond Mountains are in a lower plate rather than in a klippe means that this area is an inappropriate model for the Eleana Range near Yucca Mountain.

  10. Pliocene transpressional modification of depositional basins by convergent thrusting adjacent to the "Big Bend" of the San Andreas fault: An example from Lockwood Valley, southern California

    USGS Publications Warehouse

    Kellogg, K.S.; Minor, S.A.

    2005-01-01

    The "Big Bend" of the San Andreas fault in the western Transverse Ranges of southern California is a left stepping flexure in the dextral fault system and has long been recognized as a zone of relatively high transpression compared to adjacent regions. The Lockwood Valley region, just south of the Big Bend, underwent a profound change in early Pliocene time (???5 Ma) from basin deposition to contraction, accompanied by widespread folding and thrusting. This change followed the recently determined initiation of opening of the northern Gulf of California and movement along the southern San Andreas fault at about 6.1 Ma, with the concomitant formation of the Big Bend. Lockwood Valley occupies a 6-km-wide, fault-bounded structural basin in which converging blocks of Paleoproterozoic and Cretaceous crystalline basement and upper Oligocene and lower Miocene sedimentary rocks (Plush Ranch Formation) were thrust over Miocene and Pliocene basin-fill sedimentary rocks (in ascending order, Caliente Formation, Lockwood Clay, and Quatal Formation). All the pre-Quatal sedimentary rocks and most of the Pliocene Quatal Formation were deposited during a mid-Tertiary period of regional transtension in a crustal block that underwent little clockwise vertical-axis rotation as compared to crustal blocks to the south. Ensuing Pliocene and Quaternary transpression in the Big Bend region began during deposition of the poorly dated Quatal Formation and was marked by four converging thrust systems, which decreased the areal extent of the sedimentary basin and formed the present Lockwood Valley structural basin. None of the thrusts appears presently active. Estimated shortening across the center of the basin was about 30 percent. The fortnerly defined eastern Big Pine fault, now interpreted to be two separate, oppositely directed, contractional reverse or thrust faults, marks the northwestern structural boundary of Lockwood Valley. The complex geometry of the Lockwood Valley basin is similar

  11. Geology and geophysics of the southern Raft River Valley geothermal area, Idaho, USA

    USGS Publications Warehouse

    Williams, Paul L.; Mabey, Don R.; Zohdy, Adel A.R.; Hans, Ackerman; Hoover, Donald B.; Pierce, Kenneth L.; Oriel, Steven S.

    1976-01-01

    The Raft River valley, near the boundary of the Snake River plain with the Basin and Range province, is a north-trending late Cenozoic downwarp bounded by faults on the west, south, and east. Pleistocene alluvium and Miocene-Pliocene tuffaceous sediments, conglomerate, and felsic volcanic rocks aggregate 2 km in thickness. Large gravity, magnetic, and total field resistivity highs probably indicate a buried igneous mass that is too old to serve as a heat source. Differing seismic velocities relate to known or inferred structures and to a suspected shallow zone of warm water. Resistivity anomalies reflect differences of both composition and degree of alteration of Cenozoic rocks. Resistivity soundings show a 2 to 5 ohm·m unit with a thickness of 1 km beneath a large part of the valley, and the unit may indicate partly hot water and partly clayey sediments. Observed self-potential anomalies are believed to indicate zones where warm water rises toward the surface. Boiling wells at Bridge, Idaho are near the intersection of north-northeast normal faults which have moved as recently as the late (?) Pleistocene, and an east-northeast structure, probably a right-lateral fault. Deep circulation of ground water in this region of relatively high heat flow and upwelling along faults is the probable cause of the thermal anomaly.

  12. Holocene geologic slip rate for the Mission Creek strand of the Southern San Andreas Fault, northern Coachella Valley, CA.

    NASA Astrophysics Data System (ADS)

    Munoz, J. J.; Behr, W. M.; Sharp, W. D.; Fryer, R.; Gold, P. O.

    2016-12-01

    Slip on the southern San Andreas fault in the northwestern Coachella Valley in Southern California is partitioned between three strands, the Mission Creek, Garnet Hill, and Banning strands. In the vicinity of the Indio Hills, the NW striking Mission Creek strand extends from the Indio Hills into the San Bernardino Mountains, whereas the Banning and Garnet Hill strands strike WNW and transfer slip into the San Gorgonio Pass region. Together, these three faults accommodate 20 mm/yr of right-lateral motion. Determining which strand accommodates the majority of fault slip and how slip rates on these strands have varied during the Quaternary is critical to seismic hazard assessment for the southern California region. Here we present a new Holocene geologic slip rate from an alluvial fan offset along the Mission Creek strand at the Three Palms site in the Indio Hills. Field mapping and remote sensing using the B4 LiDAR data indicates that the Three Palms fan is offset 57 +/- 3 meters. U-series dating on pedogenic carbonate rinds collected at 25-100 cm depth within the fan deposit constrain the minimum depositional age to 3.49 +/- 0.92 ka, yielding a maximum slip rate of 16 +6.1/-3.8 mm/yr. This Holocene maximum slip rate overlaps within errors with a previously published late Pleistocene slip rate of 12-22 mm/yr measured at Biskra Palms, a few kilometers to the south. Cosmogenic 10Be surface exposure samples were also collected from the fan surface to bracket the maximum depositional age. These samples have been processed and are currently awaiting AMS measurement.

  13. Structural setting of the Southern Apennine fold-and-thrust belt (Italy) at hypocentral depth: The Calore Valley case history

    NASA Astrophysics Data System (ADS)

    Di Bucci, Daniela; Massa, Bruno; Tornaghi, Milly; Zuppetta, Agostino

    2006-11-01

    The reconstruction of the main structural features of the Southern Apennines (Italy), in correspondence with the focal volume of some strong earthquakes that have affected this chain, can be attempted by analysing reflection seismic lines and deep well logs in comparison with surface geology. For instance, the Calore Valley and its surroundings have been the object of intense hydrocarbon exploration, and a wealth of subsurface data is available. Moreover, this area was affected by the 1688 Sannio earthquake (macroseismic magnitude 7.1), and a new location has recently been proposed for the related causative fault system. The present work defines the structural setting of the Southern Apennine chain in correspondence with this new location, and compares it with similar cases along the Italian peninsula. The analysis was focussed on the reconstruction of deep tectonic units (formed by the buried Apulia carbonate platform succession), which generally correspond to the hypocentral depths of strong earthquakes along the axis of the Southern Apennines. The results show that the Apulia platform succession is affected by three main thrusts, locally accompanied by backthrusts. The top of this succession is relatively shallow: the maximum depth does not exceed 1.8 s TWT (i.e. about 3500 m b.s.l.), while minimum depths occur in correspondence with the ramp anticlines culminations, at ˜0.5 s TWT (i.e. at about 500 m b.s.l.). Moreover, data suggest that the underlying Paleozoic basement is possibly involved in thrusting. In a regional perspective, extensional seismogenic structures along the axis of the Southern Apennines seem to share some common characteristics. Indeed, they develop (i) in correspondence with an uplifted Paleozoic basement; (ii) at the rear of a set of thrusts that account for the shallow Apulia units; (iii) at the surface, in proximity to the leading edge of a surficial tectonic unit formed by the Apennine carbonate platform succession. The 1688 seismogenic

  14. Geomorphology and Tectonics at the Intersection of Silurian and Death Valleys, Southern California - 2005 Guidebook Pacific Cell Friends of the Pleistocene

    USGS Publications Warehouse

    Miller, David M.; Valin, Zenon C.

    2007-01-01

    This publication describes results from new regional and detailed surficial geologic mapping, combined with geomorphologic, geochronologic, and tectonic studies, in Silurian Valley and Death Valley, California. The studies address a long-standing problem, the tectonic and geomorphic evolution of the intersection between three regional tectonic provinces: the eastern California shear zone, the Basin and Range region of southern Nevada and adjacent California, and the eastern Mojave Desert region. The chapters represent work presented on the 2005 Friends of the Pleistocene field trip and meeting as well as the field trip road log.

  15. Characterizing the hydrogeologic framework of the Death Valley region, Southern Nevada and California

    USGS Publications Warehouse

    Faunt, Claudia; D'Agnese, Frank; Downey, Joe S.; Turner, A. Keith

    1993-01-01

    Three-dimensional (3-D) hydrogeologic modeling of the complex geology of the Death Valley region requires the application of a number of Geoscientific Information System (GSIS) techniques. This study, funded by United States Department of Energy as a part of the Yucca Mountain Project, focuses on an area of approximately 100,000 square kilometers (three degrees of latitude by three degrees of longitude) and extends up to ten kilometers in depth. The geologic conditions are typical of the Basin and Range province; a variety of sedimentary and igneous intrusive and extrusive rocks have been subjected to both compressional and extensional deformation. GSIS techniques allow the synthesis of geologic, hydrologic and climatic information gathered from many sources, including satellite imagery and published maps and cross-sections. Construction of a 3-D hydrogeological model is possible with the combined use of software products available from several vendors, including traditional GIS products and sophisticated contouring, interpolation, visualization, and numerical modeling packages.

  16. Ethnobotanical survey of wild food plants traditionally collected and consumed in the Middle Agri Valley (Basilicata region, southern Italy).

    PubMed

    Sansanelli, Sabrina; Ferri, Maura; Salinitro, Mirko; Tassoni, Annalisa

    2017-09-06

    This research was carried out in a scarcely populated area of the Middle Agri Valley (Basilicata region, southern Italy). The aim of the study was to record local knowledge on the traditional uses of wild food plants, as well as to collect information regarding the practices (gathering, processing and cooking) and the medicinal uses related to these plants. Fifty-eight people still possessing traditional local knowledge (TLK), 74% women and 26% men, were interviewed between May-August 2012 and January 2013, using open and semi-structured ethnobotanical interviews. For each described plant species, the botanical family, the Italian common and folk names, the plant parts used, the culinary preparation and, when present, the medicinal use, were recorded and the relative frequency of citation index (RFC) was determined. The 52 plant species mentioned by the respondents belong to 23 botanical families, with Asteraceae (12 plants) and Rosaceae (7 plants) being most frequently cited. The species with the highest RFC index is Cichorium intybus L. (0.95), followed by Sonchus spp. (S. oleraceus L., S. asper L. and S. arvensis L.) (0.76). The plant parts preferably used are leaves (22 plants), fruits (12) and stems (7). Only six wild plants were indicated as having both food use and therapeutic effect. The survey conducted on the traditional use of wild food plants in the Middle Agri Valley revealed that this cultural heritage is only partially retained by the population. Over the last few decades, this knowledge has been in fact quickly disappearing along with the people and, even in the rural context of the study area, is less and less handed down to younger generations. Nevertheless, data also revealed that the use of wild plants is recently being revaluated in a way closely related to local habits and traditions.

  17. Geophysical Studies Based on Gravity and Seismic Data of Tule Desert, Meadow Valley Wash, and California Wash Basins, Southern Nevada

    USGS Publications Warehouse

    Scheirer, Daniel S.; Page, William R.; Miller, John J.

    2006-01-01

    Gravity and seismic data from Tule Desert, Meadow Valley Wash, and California Wash, Nevada, provide insight into the subsurface geometry of these three basins that lie adjacent to rapidly developing areas of Clark County, Nevada. Each of the basins is the product of Tertiary extension accommodated with the general form of north-south oriented, asymmetrically-faulted half-grabens. Geophysical inversion of gravity observations indicates that Tule Desert and Meadow Valley Wash basins are segmented into subbasins by shallow, buried basement highs. In this study, basement refers to pre-Cenozoic bedrock units that underlie basins filled with Cenozoic sedimentary and volcanic units. In Tule Desert, a small, buried basement high inferred from gravity data appears to be a horst whose placement is consistent with seismic reflection and magnetotelluric observations. Meadow Valley Wash consists of three subbasins separated by basement highs at structural zones that accommodated different styles of extension of the adjacent subbasins, an interpretation consistent with geologic mapping of fault traces oblique to the predominant north-south fault orientation of Tertiary extension in this area. California Wash is a single structural basin. The three seismic reflection lines analyzed in this study image the sedimentary basin fill, and they allow identification of faults that offset basin deposits and underlying basement. The degree of faulting and folding of the basin-fill deposits increases with depth. Pre-Cenozoic units are observed in some of the seismic reflection lines, but their reflections are generally of poor quality or are absent. Factors that degrade seismic reflector quality in this area are rough land topography due to erosion, deformed sedimentary units at the land surface, rock layers that dip out of the plane of the seismic profile, and the presence of volcanic units that obscure underlying reflectors. Geophysical methods illustrate that basin geometry is more

  18. 3-D Velocity Model of the Coachella Valley, Southern California Based on Explosive Shots from the Salton Seismic Imaging Project

    NASA Astrophysics Data System (ADS)

    Persaud, P.; Stock, J. M.; Fuis, G. S.; Hole, J. A.; Goldman, M.; Scheirer, D. S.

    2014-12-01

    We have analyzed explosive shot data from the 2011 Salton Seismic Imaging Project (SSIP) across a 2-D seismic array and 5 profiles in the Coachella Valley to produce a 3-D P-wave velocity model that will be used in calculations of strong ground shaking. Accurate maps of seismicity and active faults rely both on detailed geological field mapping and a suitable velocity model to accurately locate earthquakes. Adjoint tomography of an older version of the SCEC 3-D velocity model shows that crustal heterogeneities strongly influence seismic wave propagation from moderate earthquakes (Tape et al., 2010). These authors improve the crustal model and subsequently simulate the details of ground motion at periods of 2 s and longer for hundreds of ray paths. Even with improvements such as the above, the current SCEC velocity model for the Salton Trough does not provide a match of the timing or waveforms of the horizontal S-wave motions, which Wei et al. (2013) interpret as caused by inaccuracies in the shallow velocity structure. They effectively demonstrate that the inclusion of shallow basin structure improves the fit in both travel times and waveforms. Our velocity model benefits from the inclusion of known location and times of a subset of 126 shots detonated over a 3-week period during the SSIP. This results in an improved velocity model particularly in the shallow crust. In addition, one of the main challenges in developing 3-D velocity models is an uneven stations-source distribution. To better overcome this challenge, we also include the first arrival times of the SSIP shots at the more widely spaced Southern California Seismic Network (SCSN) in our inversion, since the layout of the SSIP is complementary to the SCSN. References: Tape, C., et al., 2010, Seismic tomography of the Southern California crust based on spectral-element and adjoint methods: Geophysical Journal International, v. 180, no. 1, p. 433-462. Wei, S., et al., 2013, Complementary slip distributions

  19. Constraints on the post-middle-Pleistocene tectonic development of the Confidence Hills, southern Death Valley, California

    NASA Astrophysics Data System (ADS)

    Goodman, J. T.; Caskey, S. J.

    2009-12-01

    Our recent field mapping and tephrochronology offers new constraints on the style, timing, and rates of middle-Pleistocene-to-recent deformation in the Confidence Hills (CH), southern Death Valley. Movement on the active trace of the Southern Death Valley fault zone (SDVFZ) was preceded by earlier large-scale, northeast-vergent folding. This earlier folding involves several hundred meters of conformable late-Pliocene-to-middle-Pleistocene strata, which together form the common limb of a locally overturned fault-propagation fold pair. Geometric relations require that the blind thrust(s) responsible for earlier folding in the CH root well to the southwest of the active trace of the SDVFZ, which raises questions concerning previous flower structure models for earlier folding in the CH. Earlier folding began after deposition of Upper Glass Mountain tephra (1.1-0.9 Ma), which lies within the uppermost section of conformable, locally overturned Confidence Hills Formation(CHF), and ended prior to deposition of unconformably overlying fanglomerate, which contain tephra layers we tentatively correlate to the Bishop (0.76 Ma) and Lava Creek B (0.64 Ma) tephra. Earlier folding resulted in greater than 400 m structural relief and nearly 600 m of shortening in the span of 140-340 ka, yielding a middle-Pleistocene shortening rate of ~1.8-4.3 mm/yr. Dextral slip along the mappable traces of the SDVFZ began after earlier fault-propagation folding and also after deposition of the 0.76-0.64-Ma fanglomerates. Net right-lateral offset along the fault zone is well constrained ~4-km south of Shoreline Butte where a steeply-dipping contact marking the base of volcaniclastic conglomerate of the CHF is offset ~650 m. These relations yield a minimum post-middle-Pleistocene slip rate of ~1 mm/yr for the SDVFZ. Post-0.64-Ma shortening within the CH has been minor relative to earlier folding. The earlier fault-propagation folding in the CH appears to be related to a short-lived episode of

  20. High-precision U-Pb geochronology in the Minnesota River Valley subprovince and its bearing on the Neoarchean to Paleoproterozoic evolution of the southern Superior Province

    USGS Publications Warehouse

    Schmitz, M.D.; Bowring, S.A.; Southwick, D.L.; Boerboom, Terrence; Wirth, K.R.

    2006-01-01

    High-precision U-Pb ages have been obtained for high-grade gneisses, late-kinematic to postkinematic granitic plutons, and a crosscutting mafic dike of the Archean Minnesota River Valley tectonic subprovince, at the southern ramparts of the Superior craton of North America. The antiquity of the Minnesota River Valley terranes is confirmed by a high-precision U-Pb zircon age of 3422 ?? 2 Ma for a tonalitic phase of the Morton Gneiss. Voluminous, late-kinematic monzogranites of the Benson (Ortonville granite) and Morton (Sacred Heart granite) blocks yield identical crystallization ages of 2603 ?? 1 Ma, illustrating the synchrony and rapidity of deep crustal melting and plutonism throughout the Minnesota River Valley terranes. Postkinematic, 2591 ?? 2 Ma syenogranites and aplitic dikes in both blocks effectively constrain the final penetrative deformation of the Minnesota River Valley subprovince. Monazite growth from 2609 to 2595 Ma in granulitic paragneisses of the Benson and Montevideo blocks is interpreted to record prograde to peak granulite facies metamorphic conditions associated with crustal thickening and magmatism. Neoarchean metamorphism and plutonism are interpreted to record the timing of collisional accretion and terminal suturing of the Mesoarchean continental Minnesota River Valley terranes to the southern margin of the Superior Province, along the western Great Lakes tectonic zone. Subsequent Paleoproterozoic rifting of this margin is recorded by voluminous basaltic dike intrusion, expressed in the Minnesota River Valley by major WNW-trending tholeiitic diabase dikes dated at 2067 ?? 1 Ma, only slightly younger than the structurally and geochemically similar 2077 ?? 4 Ma Fort Frances (Kenora-Kabetogama) dike swarm of northern Minnesota and adjoining Canada. ?? 2006 Geological Society of America.

  1. Early Eocene Molluscan biostratigraphy, Mount Pinos-Lockwood Valley area, northern Ventura County, southern California

    SciTech Connect

    Squires, R.L.; Wilson, M.

    1987-05-01

    A 600-m thick unnamed marine, predominantly transition-zone siltstone unit along the south flank of the Mount Pinos uplift, in the northern Lockwood Valley area, previously has been suggested to be early Eocene (Capay Stage) in age at its base. This present study shows the entire unit to be this age. Unconformably overlying the pre-Tertiary granite basement is 30 m of unfossiliferous muddy siltstone that grades upward into 50 m of very fine sandstone with rarely fossiliferous lenses of medium to coarse sandstone. Gradationally above the sandstone is 100 m of muddy siltstone with less rarely fossiliferous lenses of conglomeratic sandstone. Macrofossil collections made at 10 localities in these lower 180 m yielded a sparse fauna of subtropical shallow-marine gastropods and bivalves, as well as rare specimens of discocyclinid foraminifera. from 180 to 500 m above the base of the section is unfossiliferous siltstone with local occurrences of lower shoreface, alternating laminated and bioturbated very fine sandstone. The uppermost 100 m of the section is siltstone with rarely fossiliferous lenses of fine to medium sandstone. Collections made at five localities yielded subtropical shallow-marine mollusks. Evidence of a West Coast provincial molluscan Capay Stage (early Eocene) age for all the fossiliferous beds of the siltstone unit is the presence of Turritella andersoni, a species diagnostic of this stage. Commonly associated mollusks are Cryptoconus cooperi, Cylichnina tantilla, Ectinochilus (Macilentos) macilentus, and Turritella buwaldana. Unconformably overlying the unit is the Oligocene-lower Miocene nonmarine Plush Ranch Formation.

  2. A Study of the Connection Among Basin-Fill Aquifers, Carbonate-Rock Aquifers, and Surface-Water Resources in Southern Snake Valley, Nevada

    USGS Publications Warehouse

    ,

    2008-01-01

    The Secretary of the Interior through the Southern Nevada Public Lands Management Act approved funding for research to improve understanding of hydrologic systems that sustain numerous water-dependent ecosystems on Federal lands in Snake Valley, Nevada. Some of the streams and spring-discharge areas in and adjacent to Great Basin National Park have been identified as susceptible to ground-water withdrawals (Elliott and others, 2006) and research has shown a high potential for ground-water flow from southern Spring Valley into southern Snake Valley through carbonate rocks that outcrop along a low topographic divide known as the Limestone Hills (Welch and others, 2007). Comprehensive geologic, hydrologic, and chemical information will be collected and analyzed to assess the hydraulic connection between basin-fill aquifers and surface-water resources, water-dependent ecological features, and the regional carbonate-rock aquifer, the known source of many high-discharge springs. Understanding these connections is important because proposed projects to pump and export ground water from Spring and Snake Valleys in Nevada may result in unintended capture of water currently supplying springs, streams, wetlands, limestone caves, and other biologically sensitive areas (fig. 1). The methods that will be used in this study may be transferable to other areas in the Great Basin. The National Park Service, Bureau of Land Management, U.S. Fish and Wildlife Service, and U.S. Forest Service submitted the proposal for funding this research to facilitate science-based land management. Scientists from the U.S. Geological Survey (USGS) Water Resources and Geologic Disciplines, and the University of Nevada, Reno, will accomplish four research elements through comprehensive data collection and analysis that are concentrated in two distinct areas on the eastern and southern flanks of the Snake Range (fig. 2). The projected time line for this research is from July 2008 through September 2011.

  3. Evaluation of the groundwater flow model for southern Utah and Goshen Valleys, Utah, updated to conditions through 2011, with new projections and groundwater management simulations

    USGS Publications Warehouse

    Brooks, Lynette E.

    2013-01-01

    The U.S. Geological Survey (USGS), in cooperation with the Southern Utah Valley Municipal Water Association, updated an existing USGS model of southern Utah and Goshen Valleys for hydrologic and climatic conditions from 1991 to 2011 and used the model for projection and groundwater management simulations. All model files used in the transient model were updated to be compatible with MODFLOW-2005 and with the additional stress periods. The well and recharge files had the most extensive changes. Discharge to pumping wells in southern Utah and Goshen Valleys was estimated and simulated on an annual basis from 1991 to 2011. Recharge estimates for 1991 to 2011 were included in the updated model by using precipitation, streamflow, canal diversions, and irrigation groundwater withdrawals for each year. The model was evaluated to determine how well it simulates groundwater conditions during recent increased withdrawals and drought, and to determine if the model is adequate for use in future planning. In southern Utah Valley, the magnitude and direction of annual water-level fluctuation simulated by the updated model reasonably match measured water-level changes, but they do not simulate as much decline as was measured in some locations from 2000 to 2002. Both the rapid increase in groundwater withdrawals and the total groundwater withdrawals in southern Utah Valley during this period exceed the variations and magnitudes simulated during the 1949 to 1990 calibration period. It is possible that hydraulic properties may be locally incorrect or that changes, such as land use or irrigation diversions, occurred that are not simulated. In the northern part of Goshen Valley, simulated water-level changes reasonably match measured changes. Farther south, however, simulated declines are much less than measured declines. Land-use changes indicate that groundwater withdrawals in Goshen Valley are possibly greater than estimated and simulated. It is also possible that irrigation

  4. Investigation of the southern limits of Murray Valley encephalitis activity in Western Australia during the 2000 wet season.

    PubMed

    Broom, Annette K; Lindsay, Michael D A; Harrington, Susan A; Smith, David W

    2002-01-01

    Western Australia experienced its worst-ever outbreak of the mosquito-borne Murray Valley encephalitis (MVE) virus during the 2000 wet season. Highest-on-record rainfall throughout much of the state during the 2000 wet season gave rise to extensive mosquito breeding and increased MVE virus transmission, resulting in nine cases of encephalitis. Activity of MVE virus in Western Australia is monitored by detecting MVE virus-specific antibodies in serum from sentinel chickens, located at towns and communities throughout the north of the state. However, during 2000, all 28 flocks of chickens seroconverted to MVE virus, including a flock located >600 km further south than MVE virus activity had ever previously been recorded. Furthermore, the majority of the nine cases of encephalitis occurred outside the enzootic Kimberley region. We therefore undertook a major serosurvey of domestic chicken flocks both south and east of the previously defined regions of virus activity. The results suggest that MVE virus activity extended as far south as the Midwest and northern Goldfields during 2000. A new southern limit of activity of MVE virus is therefore proposed. The results have implications for managing outbreaks of MVE virus in Western Australia and have enabled us to locate additional sentinel flocks as part of the MVE surveillance program for future years.

  5. Paleomagnetic Definition of Domains and Quaternary Block-Rotations in the East Ventura Basin and San Fernando Valley, Southern California

    NASA Astrophysics Data System (ADS)

    Levi, S.; Levi, S.; Yeats, R. S.

    2001-12-01

    The San Fernando Valley and east Ventura basin in southern California, the region of the 1994 Northridge earthquake and the LARSE 2 deep crustal profile, are fragmented into domains up to tens of kilometers in linear dimension. These domains were determined from paleomagnetic studies of the Pliocene-Quaternary Saugus Formation, which was deposited between 2.3 and 0.4 Ma based on a magnetostratigraphic section described by Levi and Yeats (1993, Tectonics). In two of the four domains, southwest of and adjacent to the San Gabriel fault, the Saugus shows significant Quaternary clockwise rotation (Magic Mountain, 30o; Kagel Ridge, 34o). The two other domains are unrotated (Soledad Canyon, northeast of and adjacent to the San Gabriel fault immediately across the fault from the Magic Mountain domain, and the Van Norman reservoir in the south limb of the Mission Hills syncline, directly south of the Santa Susana fault and southeast of the Magic Mountain domain). The fragmentation and clockwise rotation represent crustal response to complex dextral shear between the Pacific and North America plates. The response of individual domains is dictated by their geometry and zones of interaction along boundaries with adjacent domains. The relatively small size of the domains might impose an upper limit on magnitude of local crustal earthquakes.

  6. Airborne grass and ragweed pollen in the southern Panonnian Valley--consideration of rural and urban environment.

    PubMed

    Sikoparija, Branko; Radisic, Predrag; Pejak, Tatjana; Simic, Smiljka

    2006-01-01

    The aims of this study were to describe and compare the characteristics of grass and ragweed airborne pollen in rural and urban areas in the southern Panonnian Valley. Airborne pollen data were collected by using Hirst type volumetric samplers simultaneously in rural and urban localities. If rural and urban environment are considered, both grass and ragweed daily pollen concentrations showed a significant degree of association. Observed parameters (pollen index, maximum daily concentration, number of days during which the pollen is recorded in the air and start day of main pollen season), showed year-to-year variations for both grass and ragweed aeropollen. Average values of these parameters were higher in the rural environment, but the difference was statistically significant only for grass pollen index. Such a low difference indicates the possibility for conducting dose response clinical trials based on data obtained from one sampling station. The least year-to-year variations as well as the least difference between rural and urban environment, have been observed in the case of start date of the MPS. Such a situation suggests the possibility for using data obtained in one type of environment for the development of long-term forecast models for an entire region.

  7. Relief Inversion in the Avrona Playa as Evidence of Large-Magnitude Historical Earthquakes, Southern Arava Valley, Dead Sea Rift

    NASA Astrophysics Data System (ADS)

    Amit, Rivka; Zilberman, Ezra; Porat, Naomi; Enzel, Yehouda

    1999-07-01

    The Arava Valley section of the Dead Sea Transform (DST) in southern Israel is characterized by the absence of seismic activity in recent times. However, paleoseismic analysis of sediments in the Avrona Playa, a pull-apart basin along the DST, reveals that at least six M > 6 tectonic events have affected the Avrona playa in the last 14,000 yr. The recurrence interval of the events is approximately 2000 yr. Trenched normal faults and push-up ridges in the playa show that the upper 2 m of the deformed sedimentary sequence consists of playa deposits with uniform soil development. The deformed sediments and the soil are typical of basins with an endoreic fluvial system. Based on the limiting age of the sequence and the extent of soil development, faulting in the playa, followed by compression and uplift, occurred in the last 1000 yr. This most recent tectonic event displaced the surface by at least 1 m, consistent with a M > 6.5 earthquake. This earthquake changed the morphology of the Avrona Playa from a closed system with internal drainage to an open basin, resulting in relief inversion. The seismic quiescence in the Arava may indicate a seismic gap in this segment of the DST.

  8. Aquatic Insect Emergence in Post-Harvest Flooded Agricultural Fields in the Southern San Joaquin Valley, California

    NASA Astrophysics Data System (ADS)

    Moss, R. C.; Blumenshine, S.; Fleskes, J.

    2005-05-01

    California's Southern San Joaquin Valley is one of the most important waterbird areas in North America, but has suffered a disproportionate loss of wetlands when compared to other California regions. This project analyzes the habitat value of post-harvest flooded cropland by measuring the emergence of aquatic insects across multiple crop types. Aquatic insect emergence was sampled from post-harvest flooded fields of four crop types (alfalfa, corn, tomato, wheat), August-October, 2003-2004. Emergence was measured using traps deployed with a stratified random distribution to sample between and within field variation. Emergence rate and emergent biomass was significantly higher in flooded tomato fields. Results from corn fields indicate that flooding depth was correlated (r=0.095) with both diel temperature fluctuation and emergence rate. Chironomus dilutus larvae were grown in environmental chambers, under two thermal treatments with the same mean but different amplitudes (high: 15°-32°C, low: 20°-26°C) to investigate thermal fluctuation effects on survival and biomass. Larval survival (4x) and biomass (2x) were significantly greater in the low versus high temperature fluctuation treatment. This research has the potential to affect agricultural management throughout the 12,600 km2 region, increase aquatic insect production and aid in the recovery of declining bird populations.

  9. Diagenesis of Miocene, incised valley-filling limestones; Provence, Southern France

    NASA Astrophysics Data System (ADS)

    Seibel, Margaret J.; James, Noel P.

    2017-01-01

    The Cenozoic of southeastern France is characterized by a series of incised valleys that were filled by a succession of marine carbonate and then siliciclastic sediments culminating in the modern Rhone River depositional system. The earliest of these paleovalleys (Miocene - Burdigalian) is located in the Pernes Hills between the towns of Saumane and Venasque. It was filled by a succession of marine carbonates in the form of two third-order stratigraphic sequences (S1 and S2) and three fourth-order subsequences (S1a, S1b and S1c). The deposits are heterozoan throughout, composed of echinoids, bryozoans, coralline algae, mollusks, and benthic foraminifers. They comprise a succession of spectacular cross-bedded calcarenites that accumulated in the seaward part of a tide-dominated estuary. Diagenesis is interpreted to have taken place in four stages: 1) minor synsedimentary precipitation of inclusion-rich carbonate cements, 2) shallow burial physical and chemical compaction, 3) subaerial exposure and widespread precipitation of clear, zoned, epitaxial and isopachous, followed by subsequent clear, unzoned, calcite cements and, 4) prolonged subaerial exposure (middle Miocene to Holocene), that involved dissolution, karstification, and precipitation of minor clear and locally pendant calcite cement. The rocks were essentially uncemented during shallow burial only to be well lithified during the early phases of subsequent telogenesis. The main controls on such lithification are interpreted to have been: 1) the dissolution of minor aragonite biofragments and precipitation of some LMC cement, 2) the abundance of echinoid particle nuclei for epitaxial cement nucleation, and 3) increasing rainfall together with regional tectonic uplift to the east that resulted in increased subsurface water flow. This study not only emphasizes the variable paragenesis of calcite-rich, heterozoan carbonates but also highlights the utility of these Cenozoic limestones with extant components as

  10. Timing and slip for prehistoric earthquakes on the Superstition Mountain Fault, Imperial Valley, southern California

    NASA Astrophysics Data System (ADS)

    Gurrola, Larry D.; Rockwell, Thomas K.

    1996-03-01

    Trenches excavated across the Superstition Mountain fault in the Imperial Valley, California, have exposed evidence for four prehistorical earthquakes preserved in displaced lacustrine stratigraphy associated with ancient Lake Cahuilla. The presence of shoreline peat accumulations along with abundant detrital charcoal allows for high-precision age determination of some stratigraphic units, thereby providing constraints on the timing of three of the paleoearthquakes. These three events occurred within a 480- to 820-year interval during the past 1200 years. The most recent earthquake (event 1) occurred during a fluvial phase of deposition between A.D. 1440-1637, immediately prior to the inundation of the Cahuilla basin at about A.D. 1480 and 1660. A channel margin was offset 2.2 +0.4/-0.15 m in this rupture, suggesting an earthquake with a magnitude ≥7. The penultimate event (event 2) also occurred during fluvial deposition after A.D. 1280 but before another lakestand at A.D. 1440-1640. Lateral slip could not be resolved for event 2. However, based on juxtaposition of dissimilar units and the amount of deformation produced by this event, it is presumed that this was also a large earthquake. The timing of event 3 is constrained to have occurred between about A.D. 820 and 1280. This event is represented by several fractures and small displacements that rupture up to a distinct stratigraphic level or event horizon. Slip was not resolved for this event. Finally, the timing of event 4 is very poorly constrained to between A.D. 964 and 4670 B.C. Undoubtedly, many events may have occurred during this period. Notably, the past three earthquakes occurred within a period of less than 820 years, and it has been over 350 years since the last earthquake.

  11. Valley-fill alluviation during the Little Ice Age (ca. A.D. 1400-1880), Paria River basin and southern Colorado Plateau, United States

    USGS Publications Warehouse

    Hereford, R.

    2002-01-01

    Valley-fill alluvium deposited from ca. A.D. 1400 to 1880 is widespread in tributaries of the Paria River and is largely coincident with the Little Ice Age epoch of global climate variability. Previous work showed that alluvium of this age is a mappable stratigraphic unit in many of the larger alluvial valleys of the southern Colorado Plateau. The alluvium is bounded by two disconformities resulting from prehistoric and historic arroyo cutting at ca. A.D. 1200-1400 and 1860-1910, respectively. The fill forms a terrace in the axial valleys of major through-flowing streams. This terrace and underlying deposits are continuous and interfinger with sediment in numerous small tributary valleys that head at the base of hillslopes of sparsely vegetated, weakly consolidated bedrock, suggesting that eroded bedrock was an important source of alluvium along with in-channel and other sources. Paleoclimatic and high-resolution paleoflood studies indicate that valley-fill alluviation occured during a long-term decrease in the frequency of large, destructive floods. Aggradation of the valleys ended about A.D. 1880, if not two decades earlier, with the beginning of historic arroyo cutting. This shift from deposition to valley entrenchment near the close of the Little Ice Age generally coincided with the beginning of an episode of the largest floods in the preceding 400-500 yr, which was probably caused by an increased recurrence and intensity of flood-producing El Nin??o events beginning at ca. A.D. 1870.

  12. Shallow Creep Along the Southern Longitudinal Valley Fault in Eastern Taiwan Constrained by Multiple Geodetic Approaches

    NASA Astrophysics Data System (ADS)

    Lai, Yen-Po; Ching, Kuo-En; Chuang, Ray Y.; Wang, Kelin; Yen, Jiun-Yee; Lee, Jian-Cheng

    2017-04-01

    We integrate the near-fault data from 10 campaign-mode GPS stations and the data from 25 continuous GPS stations and from PSInSAR, total station measurement and Photogrammetry method for recognizing the spatiotemporal variation of the kinematics at shallow part of the Chihshang fault in SE Taiwan, which has been considered to show interseismic creep near the surface. The GPS coordinate daily solutions were calculated using the software Bernese v.5.0 under the ITRF2008. The horizontal velocities estimated from coordinate time series by least squares method is relative to the station S01R in the stable continental margin of the Penghu Island in the Taiwan strait. The far-field continuous GPS horizontal velocities during January 2012 - October 2016 decrease, from east to west, from 84.4 mm/yr at the eastern coastline, 62.5 mm/yr at the hanging wall close to the fault, 45.3 mm/yr at the footwall of the fault, to 24.8 mm/yr at the Central Range. This velocity pattern reflects the fault kinematics at deep part of the fault is stably moving over time. The PSInSAR mean velocities from January 2007 to December 2010 show a localized shortening rate of up to 10 mm/yr in the line-of-sight component across the Chihshang fault, consistent with the shallow creep reaching to the surface. However, no significant velocity discontinuity is observed across the southern segments of the Chihshang fault based on the near-fault campaign-mode GPS results ( 30-meter station spacing) and from both total station measurement and Photogrammetry between January 2012 and October 2016, which implies the shallow part of the fault is locked. Because this locked behavior is continued over four years and is not a seasonal signal, we therefore propose this phenomenon as a transient locked event at the creeping segment of the fault. In addition, a slow-down creeping rate has been ever detected at the northern Chihshang fault in Chihshang area before the 2003 Mw 6.8 Cheng Kung earthquake. This transient

  13. Simulating Evapotranspiration In The DrÂa Valley, Southern Morocco: Model Sensitivity To Surface Properties

    NASA Astrophysics Data System (ADS)

    Hübener, H.; Sogalla, M.; Kerschgens, M.

    Within the interdisciplinary project IMPETUS (an integrated approach to the efficient management of scarce water resources in West Africa) the effect of interaction be- tween the earth's surface and atmosphere on fresh water availability is investigated. In this study the focus is laid upon model studies for for regions north and south of the Sahara. At the high-resolution end of the meteorological model chain employed in IMPETUS, simulations with the non-hydrostatic mesoscale model FOOT3DK (Flow Over Orographically structured Terrain, 3-Dimensional, Cologne-version) are carried out for two subcatchments in Morocco and Benin. The main objectives are: 1) to estab- lish high-resolution, area covering data-sets of evaporation, precipitation and related quantities, and 2) to assess the sensitivity of the atmospheric branch of the hydro- logical cycle to variations in the land surface. For this purpose, FOOT3DK is nested into the Local-Model (LM) of the German Weather Service (DWD), which is used for episode simulations within IMPETUS. For a first case study sensitivity tests have been carried out with FOOT3DK on 3 km horizontal resolution for the mid and lower Drâa valley in Morocco, south of the Atlas mountains. Special emphasis is given to response of the model to heterogeneities in soil water content and in soil type. Considering the response to heterogeneities in soil water content, two different methods were used to artificially enhance the water ressources available for transpiration. Results show not only enhanced transpiration rates, but also changes in near surface atmospheric flow patterns. This is due to stabilisation of the atmosphere on account of reduced near surface temperatures associated with enhanced evapotranspiration. To examine the model sensitivity to soil types, the uniform soil type taken from LM-simulations is replaced by a more realistic height dependent soil type distribution. Simulations show only small sensitivity to these changes

  14. Estimating sources of Valley Fever pathogen propagation in southern Arizona: A remote sensing approach

    NASA Astrophysics Data System (ADS)

    Pianalto, Frederick S.

    Coccidioidomycosis (Valley Fever) is an environmentally-mediated respiratory disease caused by the inhalation of airborne spores from the fungi Coccidioides spp. The fungi reside in arid and semi-arid soils of the Americas. The disease has increased epidemically in Arizona and other areas within the last two decades. Despite this increase, the ecology of the fungi remains obscure, and environmental antecedents of the disease are largely unstudied. Two sources of soil disturbance, hypothesized to affect soil ecology and initiate spore dissemination, are investigated. Nocturnal desert rodents interact substantially with the soil substrate. Rodents are hypothesized to act as a reservoir of coccidioidomycosis, a mediator of soil properties, and a disseminator of fungal spores. Rodent distributions are poorly mapped for the study area. We build automated multi-linear regression models and decision tree models for ten rodent species using rodent trapping data from the Organ Pipe Cactus National Monument (ORPI) in southwest Arizona with a combination of surface temperature, a vegetation index and its texture, and a suite of topographic rasters. Surface temperature, derived from Landsat TM thermal images, is the most widely selected predictive variable in both automated methods. Construction-related soil disturbance (e.g. road construction, trenching, land stripping, and earthmoving) is a significant source of fugitive dust, which decreases air quality and may carry soil pathogens. Annual differencing of Landsat Thematic Mapper (TM) mid-infrared images is used to create change images, and thresholded change areas are associated with coordinates of local dust inspections. The output metric identifies source areas of soil disturbance, and it estimates the annual amount of dust-producing surface area for eastern Pima County spanning 1994 through 2009. Spatially explicit construction-related soil disturbance and rodent abundance data are compared with coccidioidomycosis

  15. An evolved axial melt lens in the Northern Ibra Valley, Southern Oman Ophiolite

    NASA Astrophysics Data System (ADS)

    Loocke, M. P.; Lissenberg, C. J.; MacLeod, C. J.

    2014-12-01

    The axial melt lens (AML) is a common feature lying at the base of the upper crust at fast-spreading mid-ocean ridges. It is thought to play a major role in the evolution of MORB and, potentially, accretion of the plutonic lower crust. In order to better understand the petrological processes that operate in AMLs we have examined the nature and variability of the horizon equivalent to the AML preserved in the Oman ophiolite. We present the results of a detailed investigation of a section east of Fahrah in the Ibra Valley. Here, a suite of 'varitextured' gabbros separates the sheeted dykes above from foliated gabbros below. It comprises 3 distinct units: an ophitic gabbro with pegmatitic patches (patchy gabbro; 70 m thick), overlain by a spotty gabbro (50 m), capped by a quartz-diorite (120 m). The sheeted dykes are observed to root in the quartz-diorite. Contacts between the plutonic units are gradational and subhorizontal. All of the units are isotropic. A total of 110 samples were collected for detailed petrographic and chemical analysis. With the exception of a small number of the diorites, all of the samples have a 'cumulate' component. Primary igneous amphibole is ubiquitous, present even as a minor phase in the foliated gabbros beneath, and indicating extensive differentiation and/or the presence of water in the primary liquid. France et al. (2014, Lithos) report patches of granoblastic material from this horizon in the Fahrah area, and suggest they represent the restites of partially melted pieces of the sheeted dykes. We did not, however, find any such granoblastic material, nor can the quartz-diorites represent partial melt; instead, preliminary geochemical modeling suggests that all of the units can be related by simple progressive fractional crystallization of an Oman axial ('V1' or 'Geotimes') melt. Along with the field relationships, as well as the basaltic andesite to dacite composition of the overlying sheeted dykes, this suggests that the AML was the

  16. The Verdesca landslide in the Agri Valley (Basilicata, southern Italy): a new geological and geomorphological framework

    NASA Astrophysics Data System (ADS)

    Gueguen, E.; Bentivenga, M.; Colaiacovo, R.; Margiotta, S.; Summa, V.; Adurno, I.

    2015-11-01

    A landslide, to the west of Montemurro (a small village in southern Italy), has recently caused damage to buildings and other infrastructure in an urbanized area; as a result the development of new economic activities has been prohibited. The landslide phenomenon started in the last century and has been studied since the 1990s using classical geotechnical methods; however the sliding body continues to move. This paper presents the results of a study carried out using field surveys, geognostic investigations and TDR (time domain reflectometry) measurements in order to reconstruct the stratigraphy of the sediments involved and to further understand the geological and geomorphological context of the slope. This study is part of a larger multidisciplinary project, the results of which will also be presented in this paper. The landslide (rotational slide in the upper sector, developing into a translational slide in the lower part) affects Quaternary continental clastic deposits resting on a bedrock formed by Tertiary siliciclastic sediments of the Gorgoglione Flysch. TDR measurements did not show any significant movement during the period monitored (January 2013-January 2014). Slip zone geometries were hypothesized using inclinometric measurements taken from previous studies, stratigraphic data and geomorphological interpretations of topographic scarps. Feedback from monitoring will confirm this hypothesis.

  17. The Verdesca landslide in the Agri Valley (Basilicata, southern Italy): a new geological and geomorphological framework

    NASA Astrophysics Data System (ADS)

    Gueguen, E.; Bentivenga, M.; Colaiacovo, R.; Margiotta, S.; Summa, V.; Adurno, I.

    2015-03-01

    A landslide, to the west of Montemurro (a small village in Southern Italy), has recently caused damage to buildings and other infrastructures in an urbanized area, as a result the development of new economic activities has been prohibited. The landslide was discovered in the last century and has been studied since the 1990's using classical geotechnical methods, but the sliding body continues to move. In this paper, we will present the results of a study carried out using field surveys, geognostic investigations and TDR (Time Domain Reflectometry) measurements in order to reconstruct the stratigraphy of the sediments involved and to further understand the geological and geomorphological context of the slope. This study is part of a larger multidisciplinary project of which the results will also be presented in this paper. The landslide (rotational slide in the upper sector, developing into a translational slide in the lower part) affects Quaternary continental clastic deposits resting on a bedrock formed by Tertiary siliciclastic sediments of the Gorgoglione Flysch. TDR measurements did not show any significant movement during the period monitored (January 2013-January 2014). Slip zone geometries were hypothesized using inclinometric measurements taken from previous studies, stratigraphic data and geomorphological interpretations of topographic scarps. Feedback from monitoring will confirm this hypothesis.

  18. Paleoclimate of the Southern San Joaquin Valley, CA: Research Participation Opportunities for Improving Minority Participation and Achievement in the Geosciences

    NASA Astrophysics Data System (ADS)

    Baron, D.; Negrini, R.; Palacios-Fest, M. R.

    2004-12-01

    Numerous studies have shown that one of the best ways to draw students into geoscience programs is to expose them and their teachers to research projects designed to investigate issues relevant to their lives and communities. To be most effective, involvement in these projects should begin at the pre-college level and continue throughout their college career. Recognizing the importance of genuine research experiences, the Department of Geology at California State University, Bakersfield (CSUB), with support from the National Science Foundation's Opportunities for Enhancing Diversity in the Geosciences program, provides research participation opportunities for teachers and students from the Bakersfield City School District and the Kern High School District. Both districts have a high percentage of low-income and minority students that normally would not consider a degree or career in the geosciences. The project centers around a four-week summer research program and follow-up activities during the school year. The research investigates the climate history of the southern San Joaquin Valley as well as the frequency of flooding in the valley. Many teachers and students are familiar with periodic flooding from personal experience and are aware of the larger issue of climate change in the past and present from news reports. Thus, they can directly relate to the relevance of the research. The project draws on the faculty's expertise in paleoclimatology and geochemistry and takes advantage of CSUB's existing research facilities. Sediments in the dry lake basins of Buena Vista Lake and Kern Lake preserve a record of the regional climate history and flooding of the Kern River and its tributaries. In the first year of the project, 6 teachers and 10 high school students worked with CSUB faculty and students. Three cores from the lake basins were collected. The cores were analyzed using established geophysical, geochemical, lithological, and micropaleontological techniques

  19. Paleogeodesy of the Southern Santa Cruz Mountains Frontal Thrusts, Silicon Valley, CA

    NASA Astrophysics Data System (ADS)

    Aron, F.; Johnstone, S. A.; Mavrommatis, A. P.; Sare, R.; Hilley, G. E.

    2015-12-01

    We present a method to infer long-term fault slip rate distributions using topography by coupling a three-dimensional elastic boundary element model with a geomorphic incision rule. In particular, we used a 10-m-resolution digital elevation model (DEM) to calculate channel steepness (ksn) throughout the actively deforming southern Santa Cruz Mountains in Central California. We then used these values with a power-law incision rule and the Poly3D code to estimate slip rates over seismogenic, kilometer-scale thrust faults accommodating differential uplift of the relief throughout geologic time. Implicit in such an analysis is the assumption that the topographic surface remains unchanged over time as rock is uplifted by slip on the underlying structures. The fault geometries within the area are defined based on surface mapping, as well as active and passive geophysical imaging. Fault elements are assumed to be traction-free in shear (i.e., frictionless), while opening along them is prohibited. The free parameters in the inversion include the components of the remote strain-rate tensor (ɛij) and the bedrock resistance to channel incision (K), which is allowed to vary according to the mapped distribution of geologic units exposed at the surface. The nonlinear components of the geomorphic model required the use of a Markov chain Monte Carlo method, which simulated the posterior density of the components of the remote strain-rate tensor and values of K for the different mapped geologic units. Interestingly, posterior probability distributions of ɛij and K fall well within the broad range of reported values, suggesting that the joint use of elastic boundary element and geomorphic models may have utility in estimating long-term fault slip-rate distributions. Given an adequate DEM, geologic mapping, and fault models, the proposed paleogeodetic method could be applied to other crustal faults with geological and morphological expressions of long-term uplift.

  20. Physical activity in youth from a subsistence agriculture community in the Valley of Oaxaca, southern Mexico.

    PubMed

    Malina, Robert M; Reyes, Maria Eugenia Peña; Tan, Swee Kheng; Little, Bertis B

    2008-08-01

    Observations of activities of contemporary subsistence agricultural communities may provide insights into the lifestyle of youth of 2 to 3 generations ago. The purpose of this study was to document age- and sex-associated variation in household activities and daily steps walking to school of youth 9-17 years in an indigenous subsistence agricultural community in Oaxaca, southern Mexico. Activities during leisure were also considered. A cross-sectional survey of a rural Zapotec-speaking community was undertaken, and respondents included 118 boys and 152 girls, aged 8.7-17.9 years. Household and leisure activities were documented by questionnaire and subsequent interview. Household activities were classified by estimated intensity for before and after school and on the weekend, and an estimate of METS per day accumulated while doing chores was derived. Number of steps from home to school was estimated. Contingency table analysis and MANCOVA controlling for age was used to evaluate results. Household activities tended to cluster at light and moderate intensities in girls and at moderate to moderate-to-vigorous intensities in boys. Estimated METS per day in approximately 2 h of chores differed significantly by sex. Secondary school girls expended significantly more METS per day in chores than primary school girls, but there was no difference by school level in boys. The daily round trip from home to school was approximately 2400 steps for primary students and approximately 2700 and approximately 3100 steps for secondary boys and girls, respectively. Television viewing and participation in sports were major leisure activities for boys and girls. Daily household chores, walking, and leisure activities suggest moderately active and moderately-to-vigorously active lifestyles in girls and boys, respectively, in this indigenous subsistence agricultural community.

  1. Geologic map and cross sections of the Embudo Fault Zone in the Southern Taos Valley, Taos County, New Mexico

    USGS Publications Warehouse

    Bauer, Paul W.; Kelson, Keith I.; Grauch, V.J.S.; Drenth, Benjamin J.; Johnson, Peggy S.; Aby, Scott B.; Felix, Brigitte

    2016-01-01

    The southern Taos Valley encompasses the physiographic and geologic transition zone between the Picuris Mountains and the San Luis Basin of the Rio Grande rift. The Embudo fault zone is the rift transfer structure that has accommodated the kinematic disparities between the San Luis Basin and the Española Basin during Neogene rift extension. The eastern terminus of the transfer zone coincides with the intersection of four major fault zones (Embudo, Sangre de Cristo, Los Cordovas, and Picuris-Pecos), resulting in an area of extreme geologic and hydrogeologic complexities in both the basin-fill deposits and the bedrock. Although sections of the Embudo fault zone are locally exposed in the bedrock of the Picuris Mountains and in the late Cenozoic sedimentary units along the top of the Picuris piedmont, the full proportions of the fault zone have remained elusive due to a pervasive cover of Quaternary surficial deposits. We combined insights derived from the latest geologic mapping of the area with deep borehole data and high-resolution aeromagnetic and gravity models to develop a detailed stratigraphic/structural model of the rift basin in the southern Taos Valley area. The four fault systems in the study area overlap in various ways in time and space. Our geologic model states that the Picuris-Pecos fault system exists in the basement rocks (Picuris formation and older units) of the rift, where it is progressively down dropped and offset to the west by each Embudo fault strand between the Picuris Mountains and the Rio Pueblo de Taos. In this model, the Miranda graben exists in the subsurface as a series of offset basement blocks between the Ponce de Leon neighborhood and the Rio Pueblo de Taos. In the study area, the Embudo faults are pervasive structures between the Picuris Mountains and the Rio Pueblo de Taos, affecting all geologic units that are older than the Quaternary surficial deposits. The Los Cordovas faults are thought to represent the late Tertiary to

  2. A record of large earthquakes during the past two millennia on the southern Green Valley Fault, California

    USGS Publications Warehouse

    Lienkaemper, James J.; Baldwin, John N.; Turner, Robert; Sickler, Robert R.; Brown, Johnathan

    2013-01-01

    We document evidence for surface-rupturing earthquakes (events) at two trench sites on the southern Green Valley fault, California (SGVF). The 75-80-km long dextral SGVF creeps ~1-4 mm/yr. We identify stratigraphic horizons disrupted by upward-flowering shears and in-filled fissures unlikely to have formed from creep alone. The Mason Rd site exhibits four events from ~1013 CE to the Present. The Lopes Ranch site (LR, 12 km to the south) exhibits three events from 18 BCE to Present including the most recent event (MRE), 1610 ±52 yr CE (1σ) and a two-event interval (18 BCE-238 CE) isolated by a millennium of low deposition. Using Oxcal to model the timing of the 4-event earthquake sequence from radiocarbon data and the LR MRE yields a mean recurrence interval (RI or μ) of 199 ±82 yr (1σ) and ±35 yr (standard error of the mean), the first based on geologic data. The time since the most recent earthquake (open window since MRE) is 402 yr ±52 yr, well past μ~200 yr. The shape of the probability density function (pdf) of the average RI from Oxcal resembles a Brownian Passage Time (BPT) pdf (i.e., rather than normal) that permits rarer longer ruptures potentially involving the Berryessa and Hunting Creek sections of the northernmost GVF. The model coefficient of variation (cv, σ/μ) is 0.41, but a larger value (cv ~0.6) fits better when using BPT. A BPT pdf with μ of 250 yr and cv of 0.6 yields 30-yr rupture probabilities of 20-25% versus a Poisson probability of 11-17%.

  3. Martian Valley

    NASA Technical Reports Server (NTRS)

    2005-01-01

    21 May 2005 This Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) image shows a portion of a martian valley, perhaps long, long ago carved by a liquid such as water, in northern Terra Cimmeria. The channel that might have once run down through the valley is no longer visible; the floor is covered with large, light-toned, windblown ripples.

    Location near: 5.7oS, 227.6oW Image width: 3 km (1.9 mi) Illumination from: upper left Season: Southern Winter

  4. Comparison of peak discharges among sites with and without valley fills for the July 8-9, 2001 flood in the headwaters of Clear Fork, Coal River basin, mountaintop coal-mining region, southern West Virginia

    USGS Publications Warehouse

    Wiley, Jeffrey B.; Brogan, Freddie D.

    2003-01-01

    The effects of mountaintop-removal mining practices on the peak discharges of streams were investigated in six small drainage basins within a 7-square-mile area in southern West Virginia. Two of the small basins had reclaimed valley fills, one basin had reclaimed and unreclaimed valley fills, and three basins did not have valley fills. Indirect measurements of peak discharge for the flood of July 8-9, 2001, were made at six sites on streams draining the small basins. The sites without valley fills had peak discharges with 10- to 25-year recurrence intervals, indicating that rainfall intensities and totals varied among the study basins. The flood-recurrence intervals for the three basins with valley fills were determined as though the peak discharges were those from rural streams without the influence of valley fills, and ranged from less than 2 years to more than 100 years.

  5. Mapping the Risk of Rift Valley fever re-emergence in Southern Africa using remote sensing data

    USDA-ARS?s Scientific Manuscript database

    Rift Valley fever is a viral disease of animals and humans that occurs throughout sub-Saharan Africa, Egypt and the Arabian Peninsula. Outbreaks of the disease are episodic and closely linked to climate variability, especially widespread elevated rainfall that facilitates Rift Valley fever virus tra...

  6. Structural and geochemical constraints on the reassembly of disrupted mid-Miocene volcanoes in the Lake Mead-Eldorado Valley area of southern Nevada

    NASA Astrophysics Data System (ADS)

    Weber, Michael E.; Smith, Eugene I.

    1987-06-01

    In the Lake Mead-Eldorado Valley (LMEV) area of southern Nevada, mid-Tertiary volcanic and plutonic rocks in the River, McCullough, and Eldorado mountains lie in the upper plate of a regional detachment structure. The detachment structure and strike-slip faults of the Lake Mead fault zone are temporally and kinematically related. Strike-slip systems and normal faults (Eldorado Valley fault) serve as boundaries between regions of variable extension in the upper plate of this detachment. Geochemical correlation and geometric reconstructions suggest that prior to extension, the LMEV area was characterized by three stratovolcano complexes, each above or adjacent to a chemically correlative pluton. Geochemical correlation techniques are useful tools that may have general application in reconstructing structurally disrupted volcanic-plutonic terranes. *Present address: Department of Geology, University of North Carolina, Chapel Hill, North Carolina 27514

  7. Predictors of mistimed, and unwanted pregnancies among women of childbearing age in Rufiji, Kilombero, and Ulanga districts of Tanzania

    PubMed Central

    2014-01-01

    Background While unintended pregnancies pose a serious threat to the health and well-being of families globally, characteristics of Tanzanian women who conceive unintentionally are rarely documented. This analysis identifies factors associated with unintended pregnancies—both mistimed and unwanted—in three rural districts of Tanzania. Methods A cross-sectional survey of 2,183 random households was conducted in three Tanzanian districts of Rufiji, Kilombero, and Ulanga in 2011 to assess women’s health behavior and service utilization patterns. These households produced 3,127 women age 15+ years from which 2,199 gravid women aged 15–49 were selected for the current analysis. Unintended pregnancies were identified as either mistimed (wanted later) or unwanted (not wanted at all). Correlates of mistimed, and unwanted pregnancies were identified through Chi-squared tests to assess associations and multinomial logistic regression for multivariate analysis. Results Mean age of the participants was 32.1 years. While 54.1% of the participants reported that their most recent pregnancy was intended, 32.5% indicated their most recent pregnancy as mistimed and 13.4% as unwanted. Multivariate analysis revealed that young age (<20 years), and single marital status were significant predictors of both mistimed and unwanted pregnancies. Lack of inter-partner communication about family planning increased the risk of mistimed pregnancy significantly, and multi-gravidity was shown to significantly increase the risk of unwanted pregnancy. Conclusions About one half of women in Rufiji, Kilombero, and Ulanga districts of Tanzania conceive unintentionally. Women, especially the most vulnerable should be empowered to avoid pregnancy at their own will and discretion. PMID:25102924

  8. Groundwater quality in the shallow aquifers of the Tulare, Kaweah, and Tule Groundwater Basins and adjacent highlands areas, Southern San Joaquin Valley, California

    USGS Publications Warehouse

    Fram, Miranda S.

    2017-01-18

    Groundwater provides more than 40 percent of California’s drinking water. To protect this vital resource, the State of California created the Groundwater Ambient Monitoring and Assessment (GAMA) Program. The Priority Basin Project of the GAMA Program provides a comprehensive assessment of the State’s groundwater quality and increases public access to groundwater-quality information. The shallow aquifers of the Tulare, Kaweah, and Tule groundwater basins and adjacent highlands areas of the southern San Joaquin Valley constitute one of the study units being evaluated.

  9. Status of groundwater quality in the Southern, Middle, and Northern Sacramento Valley study units, 2005-08: California GAMA Priority Basin Project

    USGS Publications Warehouse

    Bennett, George L.; Fram, Miranda S.; Belitz, Kenneth

    2011-01-01

    Groundwater quality in the Southern, Middle, and Northern Sacramento Valley study units was investigated as part of the Priority Basin Project of the Groundwater Ambient Monitoring and Assessment (GAMA) Program. The study units are located in California's Central Valley and include parts of Butte, Colusa, Glenn, Placer, Sacramento, Shasta, Solano, Sutter, Tehama, Yolo, and Yuba Counties. The GAMA Priority Basin Project is being conducted by the California State Water Resources Control Board in collaboration with the U.S. Geological Survey and the Lawrence Livermore National Laboratory. The three study units were designated to provide spatially-unbiased assessments of the quality of untreated groundwater in three parts of the Central Valley hydrogeologic province, as well as to provide a statistically consistent basis for comparing water quality regionally and statewide. Samples were collected in 2005 (Southern Sacramento Valley), 2006 (Middle Sacramento Valley), and 2007-08 (Northern Sacramento Valley). The GAMA studies in the Southern, Middle, and Northern Sacramento Valley were designed to provide statistically robust assessments of the quality of untreated groundwater in the primary aquifer systems that are used for drinking-water supply. The assessments are based on water-quality data collected by the USGS from 235 wells in the three study units in 2005-08, and water-quality data from the California Department of Public Health (CDPH) database. The primary aquifer systems (hereinafter, referred to as primary aquifers) assessed in this study are defined by the depth intervals of the wells in the CDPH database for each study unit. The quality of groundwater in shallow or deep water-bearing zones may differ from quality of groundwater in the primary aquifers; shallow groundwater may be more vulnerable to contamination from the surface. The status of the current quality of the groundwater resource was assessed by using data from samples analyzed for volatile organic

  10. Ground-water outflow, San Timoteo-Smiley Heights area, upper Santa Ana Valley, Southern California, 1927 through 1968

    USGS Publications Warehouse

    Dutcher, L.C.; Fenzel, F.W.

    1972-01-01

    The San Timoteo-Smiley Heights area is in the upper Santa Ana Valley, San Bernardino and Riverside Counties, Calif., where the Yucaipa and San Timoteo-Beaumont ground-water basins border Bunker .Hill basin on the south between the San Jacinto and San Andreas faults. The area is broken by numerous faults, the topography is rough, and in a large part of the area few wells had been drilled prior to 196S. The alluvial deposits, which constitute the aquifers in the area, range in thickness from 0 where they lap onto exposed bedrock hills to about 1,000 feet. Beneath the southern part of the area near the San Jacinto fault the total thickness of alluvial and lacustrine deposits may be as much as 6,000 feet. The purpose of this study was to estimate ground-water outflow by an indirect method not involving balancing of the hydrologic budget. For this purpose it was necessary to estimate the permeability of the aquifer materials, the average annual hydraulic gradient, and the cross-sectional area through which the flow occurs; these values were estimated for five segments along a line of section between the San Jacinto fault and Crafton Hills. To provide data for the outflow estimates, several miles of reflection and refraction seismic traverses were made along and across the outflow section. Nineteen deep and shallow test holes were drilled; one of the deep test holes and several existing wells were pumped to obtain data on aquifer permeability. The estimated average permeabilities of the aquifer materials range from 5 gallons per day per square foot for the lower part of the San Timoteo beds of Frick (1921) and 40 gallons per day per square foot for the older alluvium to 220 gallons per day per square foot for the upper part of the San Timoteo beds. The estimated outflow in 1927 was 8,150 acre-feet. By 1967 the estimated total outflow was 5,350 acre-feet, a reduction of approximately 34 percent. During the 12-year period 1956 through 1967, however, the annual outflow

  11. Prediction, Assessment of the Rift Valley Fever Activity in East and Southern Africa 2006–2008 and Possible Vector Control Strategies

    PubMed Central

    Anyamba, Assaf; Linthicum, Kenneth J.; Small, Jennifer; Britch, Seth C.; Pak, Edwin; de La Rocque, Stephane; Formenty, Pierre; Hightower, Allen W.; Breiman, Robert F.; Chretien, Jean-Paul; Tucker, Compton J.; Schnabel, David; Sang, Rosemary; Haagsma, Karl; Latham, Mark; Lewandowski, Henry B.; Magdi, Salih Osman; Mohamed, Mohamed Ally; Nguku, Patrick M.; Reynes, Jean-Marc; Swanepoel, Robert

    2010-01-01

    Historical outbreaks of Rift Valley fever (RVF) since the early 1950s have been associated with cyclical patterns of the El Niño/Southern Oscillation (ENSO) phenomenon, which results in elevated and widespread rainfall over the RVF endemic areas of Africa. Using satellite measurements of global and regional elevated sea surface temperatures, elevated rainfall, and satellite derived-normalized difference vegetation index data, we predicted with lead times of 2–4 months areas where outbreaks of RVF in humans and animals were expected and occurred in the Horn of Africa, Sudan, and Southern Africa at different time periods from September 2006 to March 2008. Predictions were confirmed by entomological field investigations of virus activity and by reported cases of RVF in human and livestock populations. This represents the first series of prospective predictions of RVF outbreaks and provides a baseline for improved early warning, control, response planning, and mitigation into the future. PMID:20682905

  12. Prediction, assessment of the Rift Valley fever activity in East and Southern Africa 2006-2008 and possible vector control strategies.

    PubMed

    Anyamba, Assaf; Linthicum, Kenneth J; Small, Jennifer; Britch, Seth C; Pak, Edwin; de La Rocque, Stephane; Formenty, Pierre; Hightower, Allen W; Breiman, Robert F; Chretien, Jean-Paul; Tucker, Compton J; Schnabel, David; Sang, Rosemary; Haagsma, Karl; Latham, Mark; Lewandowski, Henry B; Magdi, Salih Osman; Mohamed, Mohamed Ally; Nguku, Patrick M; Reynes, Jean-Marc; Swanepoel, Robert

    2010-08-01

    Historical outbreaks of Rift Valley fever (RVF) since the early 1950s have been associated with cyclical patterns of the El Niño/Southern Oscillation (ENSO) phenomenon, which results in elevated and widespread rainfall over the RVF endemic areas of Africa. Using satellite measurements of global and regional elevated sea surface temperatures, elevated rainfall, and satellite derived-normalized difference vegetation index data, we predicted with lead times of 2-4 months areas where outbreaks of RVF in humans and animals were expected and occurred in the Horn of Africa, Sudan, and Southern Africa at different time periods from September 2006 to March 2008. Predictions were confirmed by entomological field investigations of virus activity and by reported cases of RVF in human and livestock populations. This represents the first series of prospective predictions of RVF outbreaks and provides a baseline for improved early warning, control, response planning, and mitigation into the future.

  13. Paleosols in low-order streams and valley heads in the Araucaria Plateau - Record of continental environmental conditions in southern Brazil at the end of MIS 3

    NASA Astrophysics Data System (ADS)

    Paisani, Julio Cesar; Pontelli, Marga Eliz; Osterrieth, Margarita Luisa; Paisani, Sani Daniela Lopes; Fachin, Andressa; Guerra, Simone; Oliveira, Leandro

    2014-10-01

    The Araucaria Plateau is a geomorphological unit that occupies approximately three-quarters of the terrain in the southern region of Brazil. The plateau displays different altitudinal levels (600 to <1400 m a.s.l.) that are locally recognized as remnants of planed surfaces (S8-S1). These surfaces are maintained by basic (S3-S8) and acidic (S1 and S2) volcanic flows from the Neocretaceous period of the Paraná Basin. The largest extent of this plateau is located in a humid subtropical climate zone. Colluvial, colluvial-alluvial, alluvial sediments and paleosols (Ab diagnostic horizons) occur predominantly in S2. The paleosols are located in low-hierarchical-order fossil valleys (first- to fourth-order in Strahler's stream classification) and valley heads, which are referred to as paleovalleys in this paper. We employed these paleosols as stratigraphic level markers of the pedogenesis of the regional Upper Quaternary and propose their importance as records of the paleoenvironmental conditions of the Araucaria Plateau in areas above 1200 m a.s.l. These paleosols were dated by 14C and show ages between 23.8 ± 0.05 kyr BP (28.06-29.08 kyr cal. BP) and 41.16 ± 0.48 kyr BP (44.13-45.58 kyr cal. BP). The calibrated ages are related to Marine Isotope Stage 3 (MIS 3), in which the last period of global warming occurred (approximately 60-25 kyr cal. BP). We integrated the morphological, pedogeochemical, clay fraction mineralogy, micromorphological and δC-13 analyses of five paleosols from S2 to verify the paleoenvironmental conditions of the Araucaria Plateau and its correspondence with the paleoclimatic phenomena that were identified on a global scale during MIS 3 in the Southern Hemisphere. We obtained the following conclusions: a) the properties of paleosols reflect pedological processes that are adjusted to the paleoenvironmental conditions at the end of MIS 3 and the transition to MIS 2 (Last Glacial Maximum); b) aplasmogenic partial acidolysis was the predominant

  14. Greenhouse gas sources in the southern San Joaquin Valley of California derived from Positive Matrix Factorization of CalNex 2010 observations

    NASA Astrophysics Data System (ADS)

    Guha, A.; Gentner, D. R.; Weber, R.; Baer, D. S.; Gardner, A.; Provencal, R. A.; Goldstein, A. H.

    2012-12-01

    Quantifying the contributions of methane (CH4) and nitrous oxide (N2O) emission from sources in the southern San Joaquin valley is important for validation of the statewide greenhouse gas (GHG) inventory and subsequent AB32 law (California Global Warming Solutions Act 2006) implementation. The state GHG inventory is largely based on activity data and emission factor based estimates. The "bottom-up" emission factors for CH4 and N2O have large uncertainties and there is a lack of adequate "top-down" measurements to characterize emission rates from sources. Emissions from non-CO2 GHG sources display spatial heterogeneity and temporal variability, and are thus, often, poorly characterized. The Central Valley of California is an agriculture and industry intensive region with large concentration of dairies, refineries and active oil fields which are known CH4 sources while agricultural soil management and vehicular combustion are known sources of N2O. In summer of 2010, GHG sources in the southern San Joaquin valley were investigated as part of the CalNex (California at the Nexus of Air Quality and Climate Change) campaign. Measurements of GHG gases (CO2, CH4, and N2O) and the combustion tracer CO were performed at the Bakersfield super-site over a period of six weeks using fast response lasers based on cavity enhanced absorption spectroscopy (LGR Inc. CA). Coincident measurements of hundreds of volatile organic compounds (VOCs) served as anthropogenic and biogenic tracers of the GHG sources at local and regional levels. We present the results of Positive Matrix Factorization (PMF) analysis applied to the GHGs, CO, and 60 VOCs to define dominant source emission profiles. Seven source factors were identified and used to attribute the contribution of regional sources to enhancements above the background. Dairy operations were found to be the largest CH4 source in the region with approximately 80% of the regional emissions attributed to the 'dairy' factor. Factors dominated

  15. Diurnal patterns of rainfall in a tropical Andean valley of southern Ecuador as seen by a vertically pointing K-band Doppler radar

    NASA Astrophysics Data System (ADS)

    Bendix, Jörg; Rollenbeck, Rütger; Reudenbach, Christoph

    2006-05-01

    The diurnal precipitation dynamics in an east-west-oriented valley that connects the Amazon lowlands and the inter-Andean basin of southern Ecuador (Rio San Francisco valley) is investigated by means of a K-band rain-radar profiler (located at the ECSF research station, latitude: 3° 58'S, longitude: 79° 4W) and additional remotely sensed data. A pre-dawn/dawn (5:30-6:30 LST) maximum of rainfall is found and a secondary peak is observed after noon (14:30-15:30 LST). Although the frequency distribution of rain rates reveals that a great portion of rainfall is of stratiform character, vertical profiles of rain rate and droplet concentration points to the important contribution of embedded convection and/or showers produced by local heating for the overall amount of rainfall. Specific differences in stratification and process dynamics could be found for both peak times. The pre-dawn maximum can be related to mesoscale instabilities over the Peruvian Amazon close to the south Ecuadorian border. Extended cold air drainage flow from the Andes and low-level confluence due to the concavity of the Andean chain in this area leads to convective instability in the nocturnal Amazonian boundary layer, which is extended to the study area by the predominant easterlies in the mid-troposphere. Rain clouds with at least embedded shallow convection can overflow the bordering ridges of the San Francisco valley providing rains of higher intensity at the ECSF research station. On the contrary, the afternoon convective precipitation can be caused by locally induced thermal convection at the bordering slopes (up-slope breeze system) where the ECSF station profits from precipitation off the edge of these local cells due to the narrow valley.

  16. Interbasin flow in the Great Basin with special reference to the southern Funeral Mountains and the source of Furnace Creek springs, Death Valley, California, U.S.

    USGS Publications Warehouse

    Belcher, W.R.; Bedinger, M.S.; Back, J.T.; Sweetkind, D.S.

    2009-01-01

    Interbasin flow in the Great Basin has been established by scientific studies during the past century. While not occurring uniformly between all basins, its occurrence is common and is a function of the hydraulic gradient between basins and hydraulic conductivity of the intervening rocks. The Furnace Creek springs in Death Valley, California are an example of large volume springs that are widely accepted as being the discharge points of regional interbasin flow. The flow path has been interpreted historically to be through consolidated Paleozoic carbonate rocks in the southern Funeral Mountains. This work reviews the preponderance of evidence supporting the concept of interbasin flow in the Death Valley region and the Great Basin and addresses the conceptual model of pluvial and recent recharge [Nelson, S.T., Anderson, K., Mayo, A.L., 2004. Testing the interbasin flow hypothesis at Death Valley, California. EOS 85, 349; Anderson, K., Nelson, S., Mayo, A., Tingey, D., 2006. Interbasin flow revisited: the contribution of local recharge to high-discharge springs, Death Valley, California. Journal of Hydrology 323, 276-302] as the source of the Furnace Creek springs. We find that there is insufficient modern recharge and insufficient storage potential and permeability within the basin-fill units in the Furnace Creek basin for these to serve as a local aquifer. Further, the lack of high sulfate content in the spring waters argues against significant flow through basin-fill sediments and instead suggests flow through underlying consolidated carbonate rocks. The maximum temperature of the spring discharge appears to require deep circulation through consolidated rocks; the Tertiary basin fill is of insufficient thickness to generate such temperatures as a result of local fluid circulation. Finally, the stable isotope data and chemical mass balance modeling actually support the interbasin flow conceptual model rather than the alternative presented in Nelson et al. [Nelson

  17. Interbasin flow in the Great Basin with special reference to the southern Funeral Mountains and the source of Furnace Creek springs, Death Valley, California, U.S.

    NASA Astrophysics Data System (ADS)

    Belcher, Wayne R.; Bedinger, M. S.; Back, Jennifer T.; Sweetkind, Donald S.

    2009-05-01

    SummaryInterbasin flow in the Great Basin has been established by scientific studies during the past century. While not occurring uniformly between all basins, its occurrence is common and is a function of the hydraulic gradient between basins and hydraulic conductivity of the intervening rocks. The Furnace Creek springs in Death Valley, California are an example of large volume springs that are widely accepted as being the discharge points of regional interbasin flow. The flow path has been interpreted historically to be through consolidated Paleozoic carbonate rocks in the southern Funeral Mountains. This work reviews the preponderance of evidence supporting the concept of interbasin flow in the Death Valley region and the Great Basin and addresses the conceptual model of pluvial and recent recharge [Nelson, S.T., Anderson, K., Mayo, A.L., 2004. Testing the interbasin flow hypothesis at Death Valley, California. EOS 85, 349; Anderson, K., Nelson, S., Mayo, A., Tingey, D., 2006. Interbasin flow revisited: the contribution of local recharge to high-discharge springs, Death Valley, California. Journal of Hydrology 323, 276-302] as the source of the Furnace Creek springs. We find that there is insufficient modern recharge and insufficient storage potential and permeability within the basin-fill units in the Furnace Creek basin for these to serve as a local aquifer. Further, the lack of high sulfate content in the spring waters argues against significant flow through basin-fill sediments and instead suggests flow through underlying consolidated carbonate rocks. The maximum temperature of the spring discharge appears to require deep circulation through consolidated rocks; the Tertiary basin fill is of insufficient thickness to generate such temperatures as a result of local fluid circulation. Finally, the stable isotope data and chemical mass balance modeling actually support the interbasin flow conceptual model rather than the alternative presented in Nelson et al

  18. Precipitation of lead-zinc ores in the Mississippi Valley-type deposit at Treves, Cevennes region of southern France

    USGS Publications Warehouse

    Leach, D.; Macquar, J.-C.; Lagneau, V.; Leventhal, J.; Emsbo, P.; Premo, W.

    2006-01-01

    The Trèves zinc–lead deposit is one of several Mississippi Valley-type (MVT) deposits in the Cévennes region of southern France. Fluid inclusion studies show that the ore was deposited at temperatures between approximately 80 and 150°C from a brine that derived its salinity mainly from the evaporation of seawater past halite saturation. Lead isotope studies suggest that the metals were extracted from local basement rocks. Sulfur isotope data and studies of organic matter indicate that the reduced sulfur in the ores was derived from the reduction of Mesozoic marine sulfate by thermochemical sulfate reduction or bacterially mediated processes at a different time or place from ore deposition. The large range of δ34S values determined for the minerals in the deposit (12.2–19.2‰ for barite, 3.8–13.8‰ for sphalerite and galena, and 8.7 to −21.2‰ for pyrite), are best explained by the mixing of fluids containing different sources of sulfur. Geochemical reaction path calculations, based on quantitative fluid inclusion data and constrained by field observations, were used to evaluate possible precipitation mechanisms. The most important precipitation mechanism was probably the mixing of fluids containing different metal and reduced sulfur contents. Cooling, dilution, and changes in pH of the ore fluid probably played a minor role in the precipitation of ores. The optimum results that produced the most metal sulfide deposition with the least amount of fluid was the mixing of a fluid containing low amounts of reduced sulfur with a sulfur-rich, metal poor fluid. In this scenario, large amounts of sphalerite and galena are precipitated, together with smaller quantities of pyrite precipitated and dolomite dissolved. The relative amounts of metal precipitated and dolomite dissolved in this scenario agree with field observations that show only minor dolomite dissolution during ore deposition. The modeling results demonstrate the important control of the reduced

  19. Ground-Water Quality Data in the Southern Sacramento Valley, California, 2005 - Results from the California GAMA Program

    USGS Publications Warehouse

    Milby Dawson, Barbara J.; Bennett, George L.; Belitz, Kenneth

    2008-01-01

    Ground-water quality in the approximately 2,100 square-mile Southern Sacramento Valley study unit (SSACV) was investigated from March to June 2005 as part of the Statewide Basin Assessment Project of Ground-Water Ambient Monitoring and Assessment (GAMA) Program. This study was designed to provide a spatially unbiased assessment of raw ground-water quality within SSACV, as well as a statistically consistent basis for comparing water quality throughout California. Samples were collected from 83 wells in Placer, Sacramento, Solano, Sutter, and Yolo Counties. Sixty-seven of the wells were selected using a randomized grid-based method to provide statistical representation of the study area. Sixteen of the wells were sampled to evaluate changes in water chemistry along ground-water flow paths. Four additional samples were collected at one of the wells to evaluate water-quality changes with depth. The GAMA Statewide Basin Assessment project was developed in response to the Ground-Water Quality Monitoring Act of 2001 and is being conducted by the California State Water Resources Control Board (SWRCB) in collaboration with the U.S. Geological Survey (USGS) and the Lawrence Livermore National Laboratory (LLNL). The ground-water samples were analyzed for a large number of man-made organic constituents (volatile organic compounds [VOCs], pesticides and pesticide degradates, pharmaceutical compounds, and wastewater-indicator constituents), constituents of special interest (perchlorate, N-nitrosodimethylamine [NDMA], and 1,2,3-trichloropropane [1,2,3-TCP]), naturally occurring inorganic constituents (nutrients, major and minor ions, and trace elements), radioactive constituents, and microbial indicators. Naturally occurring isotopes (tritium, and carbon-14, and stable isotopes of hydrogen, oxygen, and carbon), and dissolved noble gases also were measured to help identify the source and age of the sampled ground water. Quality-control samples (blanks, replicates, matrix spikes

  20. Evolution of Late Miocene to Contemporary Displacement Transfer Between the Northern Furnace Creek and Southern Fish Lake Valley Fault Zones and the Central Walker Lane, Western Great Basin, Nevada

    NASA Astrophysics Data System (ADS)

    Oldow, J. S.; Geissman, J. W.

    2013-12-01

    Late Miocene to contemporary displacement transfer from the north Furnace Creek (FCF) and southern Fish Lake Valley (FLVF) faults to structures in the central Walker Lane was and continues to be accommodated by a belt of WNW-striking left-oblique fault zones in the northern part of the southern Walker Lane. The WNW fault zones are 2-9 km wide belts of anastomosing fault strands that intersect the NNW-striking FCF and southern FLVF in northern Death Valley and southern Fish Lake Valley, respectively. The WNW fault zones extend east for over 60 km where they merge with a 5-10 km wide belt of N10W striking faults that marks the eastern boundary of the southern Walker Lane. Left-oblique displacement on WNW faults progressively decreases to the east, as motion is successively transferred northeast on NNE-striking faults. NNE faults localize and internally deform extensional basins that each record cumulative net vertical displacements of between 3.0 and 5.2 km. The transcurrent faults and associated basins decrease in age from south to north. In the south, the WNW Sylvania Mountain fault system initiated left-oblique motion after 7 Ma but does not have evidence of contemporary displacement. Farther north, the left-oblique motion on the Palmetto Mountain fault system initiated after 6.0 to 4.0 Ma and has well-developed scarps in Quaternary deposits. Cumulative left-lateral displacement for the Sylvania Mountain fault system is 10-15 km, and is 8-12 km for the Palmetto fault system. The NNE-striking faults that emanate from the left-oblique faults merge with NNW transcurrent faults farther north in the eastern part of the Mina deflection, which links the Owens Valley fault of eastern California to the central Walker Lane. Left-oblique displacement on the Sylvania Mountain and Palmetto Mountain fault zones deformed the Furnace Creek and Fish Lake Valley faults. Left-oblique motion on Sylvania Mountain fault deflected the FCF into the 15 km wide Cucomungo Canyon restraining

  1. Forest adjacent households' voices on their perceptions and adaptation strategies to climate change in Kilombero District, Tanzania.

    PubMed

    Balama, Chelestino; Augustino, Suzana; Eriksen, Siri; Makonda, Fortunatus B S

    2016-01-01

    Climate change is a global and local challenge to both sustainable livelihoods and economic development. Tanzania as other countries of the world has been affected. Several studies have been conducted on farmers' perceptions and adaptation to climate change in the country, but little attention has been devoted to forest adjacent households in humid areas. This study assessed this gap through assessing forest adjacent households' voices on perceptions and adaptation strategies to climate change in Kilombero District, Tanzania. Data collection involved key informant interviews, focus group discussions and household questionnaires. Results showed that the majority of households perceived changed climate in terms of temperature increase, unpredictable rainfall, frequent occurrence of floods, increased dry spells during rainy season coupled with decreased water sources and emergence of new pests and diseases. The perceived change in climate has impacted agriculture productivity as the main livelihood source. Different coping and adaptation strategies are employed. These are; crop diversification, changing cropping calendar, adopting modern farming technologies, and increasing reliance on non-timber forest products. These strategies were positively and significantly influenced by socio-economic factors including household size, residence period, land ownership and household income. The study concludes that, there are changes in climatic conditions; and to respond to these climatic changes, forest adjacent households have developed numerous coping and adaptation strategies, which were positively and significantly influenced by some socio-economic factors. The study calls for actual implementation of local climate change policies and strategies in order to enhance adaptive capacity at household level.

  2. Study of LANDSAT-D thematic mapper performance as applied to hydrocarbon exploration. [Southern Ontario, Lawton, Oklahoma; Owl Creek, Wyoming; Washington, D.C.; and Death Valley California

    NASA Technical Reports Server (NTRS)

    Everett, J. R. (Principal Investigator)

    1983-01-01

    Improved delineation of known oil and gas fields in southern Ontario and a spectacularly high amount of structural information on the Owl Creek, Wyoming scene were obtained from analysis of TM data. The use of hue, saturation, and value image processing techniques on a Death Valley, California scene permitted direct comparison of TM processed imagery with existing 1:250,000 scale geological maps of the area and revealed small outcrops of Tertiary volcanic material overlying Paleozoic sections. Analysis of TM data over Lawton, Oklahoma suggests that the reducing chemical environment associated with hydrocarbon seepage change ferric iron to soluble ferrous iron, allowing it to be leached. Results of the band selection algorithm show a suprising consistency, with the 1,4,5 combination selected as optimal in most cases.

  3. Cloud dynamics and their impact on local precipitation processes in a high mountain valley in southern Ecuador detected by satellite and ground-based remote sensing methods

    NASA Astrophysics Data System (ADS)

    Trachte, Katja; Rollenbeck, Rütger; Bendix, Jörg

    2015-04-01

    In the high Andean Mountains of southern Ecuador cloud and rainfall formation processes are strongly connected to the complex structure of the terrain. Due to local small-scale circulation systems such as mountain-valley breezes and luv-lee effects a high variability of rainfalls occur. Besides the thermally-induced convective events in the late afternoon, dynamical processes in interaction with the topography determine cloud and rainfall formation mechanisms. In the Rio San Francisco valley early morning rainfalls cloud be traced back to nocturnal katabatic-induced mesoscale convective systems (MCS) at the east Andean slopes. A further procedure is expected in a local seeding effect: frequently MCS, formed in the Amazon basin, are transported westward with the easterly trade winds. As a result of the barrier function of the Andes Mountains the lower part of the cloud system rains out at the eastern slopes, while the upper part (cap-cloud) is drifted into the inter-andean valleys. There it acts like a seeder to low stratus clouds (feeder), which occur due to high condensation rates above the canopy. On the basis of a vertical micro-rain radar (MRR), e.g. radar reflectivity and drop diameter, the seeding effects will be identified. The evaluation of the procedure is carried out with additional observational data: GOES and Nubiscope IR temperatures are employed to detect the appearance of the seeder and the height of the feeder cloud, respectively. The enhancement of the rainfalls are indicated by a disdrometer and in-situ measurements.

  4. PM1 measurements at a site close to an oil/gas pre-treatment plant (Agri Valley - southern Italy): a preliminary study

    NASA Astrophysics Data System (ADS)

    Trippetta, S.; Caggiano, R.; Sabia, S.

    2014-09-01

    A PM1 (i.e. particulate matter with an aerodynamic diameter less than 1.0 μm) short-term monitoring campaign was carried out in the Agri Valley (southern Italy) in September 2012. This area is of international concern, since it houses one of the largest European on-shore reservoirs and the largest oil/gas pre-treatment plant (i.e. the Centro Olio Val d'Agri - COVA) within an anthropised context. PM1 measurements were performed in Viggiano, the nearest town to the COVA plant and one of the most populated towns of the Agri Valley. During the study period, the PM1 daily concentrations ranged from 1.2 to 8.4 μg m-3, with a mean value of 4.6 μg m-3. Regarding the PM1 chemical composition, it can be observed that S and typical crustal elements were the most abundant constituents of the PM1 collected. By applying principal component analysis (PCA), it was pointed out that crustal soil, biomass and wood burning, secondary atmospheric reactions involving COVA plant emissions and local soil particles, and traffic were the main sources contributing to the PM1 measured in the area under study. Moreover, a possible contribution of the long-range transport of African dust was observed.

  5. A regional record of expanded Holocene wetlands and prehistoric human occupation from paleowetland deposits of the western Yarlung Tsangpo valley, southern Tibetan Plateau

    NASA Astrophysics Data System (ADS)

    Hudson, Adam M.; Olsen, John W.; Quade, Jay; Lei, Guoliang; Huth, Tyler E.; Zhang, Hucai

    2016-07-01

    The Asian Monsoon, which brings ∼80% of annual precipitation to much of the Tibetan Plateau, provides runoff to major rivers across the Asian continent. Paleoclimate records indicate summer insolation and North Atlantic paleotemperature changes forced variations in monsoon rainfall through the Holocene, resulting in hydrologic and ecologic changes in plateau watersheds. We present a record of Holocene hydrologic variability in the Yarlung Tsangpo (YT) valley of the southern Tibetan Plateau, based on sedimentology and 14C dating of organic-rich 'black mats' in paleowetlands deposits, that shows changes in wetlands extent in response to changing monsoon intensity. Four sedimentary units indicate decreasing monsoon intensity since 10.4 ka BP. Wet conditions occurred at ∼10.4 ka BP, ∼9.6 ka BP and ∼7.9-4.8 ka BP, with similar-to-modern conditions from ∼4.6-2.0 ka BP, and drier-than-modern conditions from ∼2.0 ka BP to present. Wetland changes correlate with monsoon intensity changes identified in nearby records, with weak monsoon intervals corresponding to desiccation and erosion of wetlands. Dating of in situ ceramic and microlithic artifacts within the wetlands indicates Epipaleolithic human occupation of the YT valley after 6.6 ka BP, supporting evidence for widespread colonization of the Tibetan Plateau in the early and mid-Holocene during warm, wet post-glacial conditions.

  6. Digital Elevation Model (DEM) file of topographic elevations for the Death Valley region of southern Nevada and southeastern California processed from US Geological Survey 1-degree Digital Elevation Model data files

    SciTech Connect

    Turner, A.K.; D`Agnese, F.A.; Faunt, C.C.

    1996-04-01

    Elevation data have been compiled into a digital data base for an {approx}100,000-km{sup 2} area of the southern Great Basin, the Death Valley region of southern Nevada, and SE Calif., located between lat 35{degree}N, long 115{degree}W, and lat 38{degree}N, long 118{degree}W. This region includes the Nevada Test Site, Yucca Mountain, and adjacent parts of southern Nevada and eastern California and encompasses the Death Valley regional ground-water system. Because digital maps are often useful for applications other than that for which they were originally intended, and because the area corresponds to a region under continuing investigation by several groups, these digital files are being released by USGS.

  7. The interaction between surface processes and tectonics during the late Quaternary in the Middle Volturno River valley (southern Italy): new morpho-stratigraphic constraints from fluvial terraces

    NASA Astrophysics Data System (ADS)

    Amato, Vincenzo; Patrizio Ciro Aucelli, Pietro; Cesarano, Massimo; Filocamo, Francesca; Giralt, Santiago; Leone, Natalia; Rosskopf, Carmen Maria; Scorpio, Vittoria

    2017-04-01

    The Middle Volturno River valley is located in the inner part of the Southern Apennines of Italy, between the SW slope of the Matese Massif and the NE slopes of the Caserta mountains and is underlain by Meso-Cenozoic carbonate rocks and Miocene Flysch deposits. The study sector includes the lower Calore River valley and, below the Calore-Volturno confluence, the valley portion that extends until the Triflisco gorge, from Telese village to the Volturno dam. It is generally E-W, NW-SE and NE-SW elongated and characterized by rectilinear and meandering fluvial patterns. The main infilling of the two valley portions is locally preserved as remnants of fluvial terraces hanging over the local base level up to ca. 30-40 m. It is generally interfingered with and covered by several generations of alluvial fan and travertine deposits. New Ar/Ar datings on tephra layers interbedded in the oldest generations of the alluvial fan deposits and new U/Th datings on travertine deposits, allowed to constrain the main infilling to the late Middle and the early Upper Pleistocene. Both deposits are locally covered by the Campanian Ignimbrite Formation (CI, 39 ky BP) and are interested by high-angle faults generated during extensional tectonic phases that affected this sector of the Apennine chain since the Middle Pleistocene. Furthermore, the geomorphological analyses of aerial photos and topographic maps (1:5000 in scale) highlight the presence of a flight of fluvial terraces younger than the CI deposits that can be grouped into four orders. The stratigraphical data, based on field surveys and boreholes analyses, supported by new tephrostratigraphical constraints and literature data, allow to refer the older orders (I and II) to the late Upper Pleistocene. The III and IV orders, instead, can be referred to the early Holocene and historical times, respectively. These chronological constraints allow to hypothesize that the genesis of the I and II orders seem to be driven by late

  8. Deep seated gravitational slope deformation and hydraulic vul-nerability of the low Biferno valley (Southern Italy)

    NASA Astrophysics Data System (ADS)

    Galeandro, Annalisa; Guerricchio, Alessandro; Doglioni, Angelo; Simeone, Vincenzo

    2010-05-01

    Geological and geomorphologic features of low Biferno valley are affected by a deep seated gravitational slope deformation produced by the orogenesis of Apennines whit a fulcrum located next to confluence with Cigno's stream. As a consequence of this deep deformation the low river Biferno valley is particularly vulnerable to alluvial phenomena. The work provides an analysis of this deep gravitative deformation that characterizes the examined zone: the interpretation of a Digital Elevation Model and some geological sections (produced with the aid of Geographical Information System) has shown as both basin's morphology and plano-altimetric variation of Biferno river have been affected by this phenomenon. The aim is a description of the DSGSD and the consequences on morphology of the basin and on the Biferno's course. The tectonic action has compressed and fractured this area, which is afterwards collapsed by means of a deep slide with a rupture surface probably at the interface between blue-gray clays and clayey sands. The deformation is attested by a great scarp, in which Cigno stream positioned itself at the toe, by the collapse of the zone between streams and by the features of plano-altimetric pattern of Biferno river. Biferno has to deviate its course: in order to cross the obstacle characterized by the toe of the deep slide, the river shifts from the right riverside to the left and causes erosional processes and consequent landslide. After the confluence with Cigno stream, the river has to regain energy and makes a meandering path. In this new configuration, floods can hardly get canalized in this meanders and naturally come out from the bed of ordinary flow, invading a wide zone of the valley. Then, it emerges as the presence of deep seated gravitational slope deformation could constitute an aggravating element for the vulnerability of the territory and predisposes the zone to alluvial phenomena and landslides.

  9. Assessment of atmospheric trace element concentrations by lichen-bag near an oil/gas pre-treatment plant in the Agri Valley (southern Italy)

    NASA Astrophysics Data System (ADS)

    Caggiano, R.; Trippetta, S.; Sabia, S.

    2015-02-01

    The atmospheric concentrations of 17 trace elements (Al, Ca, Cd, Cr, Cu, Fe, K, Li, Mg, Mn, Na, Ni, P, Pb, S, Ti and Zn) were measured by means of the "lichen-bag" technique in the Agri Valley (southern Italy). The lichen samples were collected from an unpolluted site located in Rifreddo forest (southern Italy), about 30 km away from the study area along the north direction. The bags were exposed to ambient air for 6 and 12 months. The exposed-to-control (EC) ratio values highlighted that the used lichen species were suitable for biomonitoring investigations. The results showed that the concentrations of almost all the examined trace elements increased with respect to the control after 6-12-month exposures. Furthermore, Ca, Al, Fe, K, Mg and S were the most abundant trace elements both in the 6-month and 12-month-exposed samples. Moreover, principal component analysis (PCA) results highlighted that the major sources of the measured atmospheric trace elements were related both to anthropogenic contributions due to traffic, combustion processes agricultural practices, construction and quarrying activities, and to natural contributions mainly represented by the re-suspension of local soil and road dusts. In addition, the contribution both of secondary atmospheric reactions involving Centro Olio Val d'Agri (COVA) plant emissions and the African dust long-range transport were also identified.

  10. Assessment of atmospheric trace element concentrations by lichen-bag near an oil/gas pre-treatment plant in the Agri Valley (southern Italy)

    NASA Astrophysics Data System (ADS)

    Caggiano, R.; Trippetta, S.; Sabia, S.

    2014-10-01

    The atmospheric concentrations of 17 trace elements (Al, Ca, Cd, Cr, Cu, Fe, K, Li, Mg, Mn, Na, Ni, P, Pb, S, Ti and Zn) were measured by means of the "lichen-bag" technique in the Agri Valley (southern Italy). The lichen samples were collected from an unpolluted site located in Rifreddo forest (southern Italy). The bags were exposed to ambient air for 6 and 12 months. The exposed-to-control (EC) ratio values highlighted that the used lichen species were suitable for biomonitoring investigations. The results showed that the concentrations of almost all the examined trace elements increased with respect to the control after 6-12 month exposures. Furthermore, Ca, Al, Fe, K, Mg and S were the most abundant trace elements both in the 6 and 12 month-exposed samples. Moreover, principal component analysis (PCA) results highlighted that the major sources of the measured atmospheric trace elements were related both to anthropogenic contributions due to traffic, combustion processes, agricultural practices, construction and quarrying activities, and to natural contributions mainly represented by the re-suspension of local soil and road dusts. In addition, the contribution both of secondary atmospheric reactions involving Centro Olio Val d'Agri (COVA) plant emissions and the African dust long-range transport were also identified.

  11. Chemical data and variation diagrams of igneous rocks from the Timber Mountain-Oasis Valley Caldera Complex, southern Nevada

    USGS Publications Warehouse

    Quinlivan, W.D.; Byers, F.M.

    1977-01-01

    Silica variation diagrams presented here are based on 162 chemical analyses of tuffs, lavas, and intrusives, representative of volcanic centers of the Timber Mountain-Oasis Valley caldera complex and cogenetic rocks of the Silent Canyon ca1dera. Most of the volcanic units sampled are shown on the U.S. Geological Survey geologic map of the Timber Mountain caldera area (I-891) and are described in U.S. Geological Survey Professional Paper 919. Early effusives of the complex, although slightly altered, are probably chemically, and petrographically, more like the calc-alkalic Fraction Tuff (Miocene) of the northern Nellis Air Force Base Bombing and Gunnery Range to the north, whereas effusives of later Miocene age, such as the Paintbrush and Timber Mountain Tuffs, are alkali-calcic.

  12. Interpretation of gravity profiles across the northern Oaxaca terrane, its boundaries and the Tehuacán Valley, southern Mexico

    NASA Astrophysics Data System (ADS)

    Campos-Enríquez, J. O.; Alatorre-Zamora, M. A.; Keppie, J. D.; Belmonte-Jiménez, S. I.; Ramón-Márquez, V. M.

    2014-12-01

    A gravity study was conducted across the northern Oaxaca terrane and its bounding faults: the Caltepec and Oaxaca Faults to the west and east, respectively. These faults juxtapose the Oaxaca terrane against the Mixteca and Juarez terranes, respectively. The Oaxaca Fault also forms the eastern boundary of the Cenozoic Tehuacán depression. On the west, at depth, the Tehuacán valley is limited by the normal buried Tehuacán Fault. This gravity study reveals that the Oaxaca Fault system gives rise to a series of east tilted basamental blocks (Oaxaca Complex). The tectonic depression is filled with Phanerozoic rocks and has a deeper depocenter to the west. The gravity data also indicate that on the west, the Oaxaca Complex, the Caltepec and Santa Lucia faults continue northwestwards beneath Phanerozoic rocks. A major E-W to NE-SW discontinuity is inferred to exist between profiles 1 and 2.

  13. Development of an Upper Cambrian rimmed shelf along the Mississippi Valley Graben, Reelfoot Rift, and the southeastern Ozarks, southern Missouri

    SciTech Connect

    Palmer, J.R. . Dept. of Natural Resources)

    1993-03-01

    The paleogeographic distribution of intrashelf basin shales and limestones in the Bonneterre (Dresbachian) and Davis (Franconian) Formations, and associated data, suggests that rimmed shelf conditions separated the central Missouri part of the shelf from the Mississippi Valley Graben (MVG) of the Reelfoot Rift to the southeast. Middle Dresbachian rocks of the intrashelf basin area, predominantly limestones, indicate a discontinuous carbonate shelf rim. The succeeding widespread shales of the Franconian intrashelf basin indicate that a continuous rim had developed. The margin of the shelf rim is preserved in part of the 4,700-ft-thick Upper Cambrian succession along the northwest margin of the Mississippi Valley Graben (MVG) of the Reelfoot Rift. Equivalent rocks within the MVG are dominantly dark shales (1,600+ ft thick). The Amoco Spence test well penetrated the rim succession on the northwest margin of the MVG. At least 11 large-scale transgressive-regressive (T-R) carbonate cycles (120--600 ft thick) have been defined in this well; 7 cycles are equivalent to the Bonneterre and Davis Formations. These latter cycles have shaly limestone, or limestone at the base, and grade upward to dolostone or coarsely crystalline dolostone, which are interpreted to be shallowing-upward, bank margin-peritidal carbonates. Northwest of the rim margin and on the southeast side of the St. Francois Mountains, rocks equivalent to the rim succession consist of a series of ramp to platform cycles made up of dolostones and local limestones. Many carbonate shelves on passive margins are rimmed. The development of this Upper Cambrian rimmed shelf along the northwest margin of the MVG suggests that failed rifts can also localized such rims.

  14. Systematic variations in stress state in the southern San Joaquin Valley: Inferences based on well-bore data and contemporary seismicity

    SciTech Connect

    Castillo, D.A.; Zoback, M.D. )

    1994-08-01

    Analysis of stress-induced well-bore breakouts in 35 wells from 10 production fields in the southern San Joaquin Valley (SSJV) indicates systematic spatial variations in the direction of the maximum horizontal stresses at three different scales. First, the regional northeast-southwest compressional stress direction seen along the western margin of the San Joaquin Valley in the Elk Hills, Kettleman Hills, and Coalinga areas, gradually changes to approximately north-south compression over a distance of 10-20 km in the SSJV. This major excursion in the stress field seen in the Yowlumne, Yowlumne North, Paloma, and Rio Viejo production fields represents an approximately 40[degrees] counterclockwise rotation in the direction of the maximum horizontal stress (MHS). This systematic reorientation is consistent with approximately north-south convergence as seen in the local fold axes and reverse faults of Pliocene age and younger. Second, at the extreme south of the SSJV in the San Emidio, Los Lobos, Pleito, Wheeler Ridge, and North Tejon fields, another systematic, but localized, reorientation in the stress field indicates an abrupt change to an approximately east-northeast-west-southwest compression over a distance of a few kilometers. This latter reorientation of MHS stress direction, which is inconsistent with the local east-west-trending fold axes and thrust faults, represents a 40-50[degrees] clockwise rotation in the stresses; this reorientation appears to be limited to oil production fields located within the inferred hanging wall of the White Wolf fault that ruptured during the 1952 Kern County earthquake. Inversion of earthquake focal mechanisms of events located below the perturbed stress field indicates approximately north-south compression. The stress drop associated with the 1952 earthquake may have been responsible for rotating the MHS stress direction, implying that the remote horizontal stresses are comparable in magnitude. 53 refs., 16 refs., 2 tabs.

  15. Evidence for Late-Paleozoic brine migration in Cambrian carbonate rocks of the central and southern Appalachians: Implications for Mississippi Valley-type sulfide mineralization

    USGS Publications Warehouse

    Hearn, P.P.; Sutter, J.F.; Belkin, H.E.

    1987-01-01

    Many Lower Paleozoic limestones and dolostones in the Valley and Ridge province of the central and southern Appalachians contain 10 to 25 weight percent authigenic potassium feldspar. This was considered to be a product of early diagenesis, however, 40Ar 39Ar analyses of overgrowths on detrital K-feldspar in Cambrian carbonate rocks from Pennsylvania, Maryland, Virginia, and Tennessee yield Late Carboniferous-Early Permian ages (278-322 Ma). Simple mass balance calculations suggest that the feldspar could not have formed isochemically, but required the flux of multiple pore volumes of fluid through the rocks, reflecting regional fluid migration events during the Late-Paleozoic Alleghanian orogeny. Microthermometric measurements of fluid inclusions in overgrowths on detrital K-feldspar and quartz grains from unmineralized rocks throughout the study area indicate homogenization temperatures from 100?? to 200??C and freezing point depressions of -14?? to -18.5??C (18-21 wt.% NaCl equiv). The apparent similarity of these fluids to fluid inclusions in ore and gangue minerals of nearby Mississippi Valley-type (MVT) deposits suggests that the regional occurrences of authigenic K-feldspar and MVT mineralization may be genetically related. This hypothesis is supported by the discovery of authigenic K-feldspar intergrown with sphalerite in several mines of the Mascot-Jefferson City District, E. Tennessee. Regional potassic alteration in unmineralized carbonate rocks and localized occurrences of MVT mineralization are both explainable by a gravity-driven flow model, in which deep brines migrate towards the basin margin under a hydraulic gradient established during the Alleghanian orogeny. The authigenic K-feldspar may reflect the loss of K during disequilibrium cooling of the ascending brines. MVT deposits are probably localized manifestations of the same migrating fluids, occurring where the necessary physical and chemical traps are present. ?? 1987.

  16. Seismic Imaging Evidence for the Extension of the Silver Creek Fault from the Southern Santa Clara Valley into the East Bay

    NASA Astrophysics Data System (ADS)

    Steedman, C. E.; Catchings, R. D.; Goldman, M. R.; Rymer, M. J.

    2003-12-01

    The San Francisco Bay is bounded by several strike-slip faults of the San Andreas fault system, including the San Andreas fault to the west and the Hayward and Calaveras faults to the east. Other faults in this complex system, however, are less well-mapped. The northwest-southeast trending Silver Creek fault (SCF) has been mapped in the southern Santa Clara Valley and seismically imaged in the northern part of the valley. Two seismic reflection profiles, gravity data, and water-well data, obtained between the Santa Clara Valley and Fremont, suggest that the SCF extends farther northwest of San Jose into the East Bay. To investigate the possible northwestward extension of the SCF into the East Bay, the USGS High Resolution Seismic Imaging Group acquired two high-resolution, combined seismic reflection and refraction profiles in the Fremont area along Coyote Creek at the southernmost San Francisco Bay. Each profile was about 1.5 km long with geophone and shot spacings of 5 m. Seismic sources were generated by a Betsy Seisgun using 8-gauge shotgun blanks in 0.3-m-deep holes. Each shot was recorded for 2 s at a sample rate of 0.5 ms on 180 channels using three Geometrics Strataview RX-60 seismographs. We observe reflections to about 1000 ms. Preliminary analysis of the data indicates shallow velocities range from 1000 to 1600 m/s in the upper 50 m with multiple low- and high-velocity zones. Shot gathers indicate unusual structure in the Coyote Creek Area (in the vicinity of Albrae Slough) along the northward projection of the SCF, suggesting that the structure may be related to the SCF. Farther northward projection of the SCF and the Albrae Slough structure aligns with a fault imaged in the San Leandro area, an INSAR lineament in the Oakland area, and a mapped fault in the Richmond area. If these indicators of faulting are all associated with the SCF, then the SCF can be interpreted to extend the length of the East Bay.

  17. Geothermal activity and hydrothermal mineral deposits at southern Lake Bogoria, Kenya Rift Valley: Impact of lake level changes

    NASA Astrophysics Data System (ADS)

    Renaut, Robin W.; Owen, R. Bernhart; Ego, John K.

    2017-05-01

    Lake Bogoria, a saline alkaline closed-lake in a drainage basin of Neogene volcanic rocks in the central Kenya Rift, is fed partly by ∼200 hot alkaline springs located in three groups along its margins. Hot springs along the midwest shoreline (Loburu, Chemurkeu) and their travertine deposits have been studied, but little is known about the geothermal activity at southern Lake Bogoria. Observations, field measurements and analyses (geochemical and mineralogical) of the spring waters and deposits, spanning three decades, show that the southern spring waters are more saline, the hydrothermal alteration there is more intense, and that most hot spring deposits are siliceous. Geothermal activity at southern Lake Bogoria (Ng'wasis, Koibobei, Losaramat) includes littoral boiling springs and geysers, with fumaroles at slightly higher elevations. Modern spring deposits are ephemeral sodium carbonates, opal-A crusts and silica gels. Local fossil spring deposits include diatomaceous silica-cemented conglomerates that formed subaqueously when the lake was then dilute and higher than today, and outlying calcite tufa deposits. In contrast, mineral deposits around neighbouring fumarole vents and sites of hydrothermal alteration include clays (kaolinite), sulfate minerals (jarosite, alunite), and Fe-oxyhydroxides linked to rising acidic fluids. When lake level falls, the zone of acidity moves downwards and may overprint older alkaline spring deposits. In contrast, rising lake level leads to lake water dilution and vents in the lower parts of the acidic zone may become dilute alkaline springs. The new evidence at Lake Bogoria shows the potential for using the mineralogy of geothermal sediments to indicate former changes in lake level.

  18. Oxygen-isotope composition of Quaternary rhyolitic and basaltic lavas in the southern Owens Valley and Kern Plateau, CA

    NASA Astrophysics Data System (ADS)

    Vazquez, J. A.; Bindeman, I. N.; Browne, B. L.

    2009-12-01

    Over the last 250 ka, the Coso volcanic field has erupted approximately 2 km3 of high-silica rhyolite during seven eruptive episodes within a central area characterized by high heat flow and a long-lived hydrothermal system. Coeval basalts are confined to the periphery of the rhyolitic center, suggesting a persistent locus of rhyolitic intrusion and a growing reservoir of silicic magma. To evaluate the generation and assembly of this evolving silicic system, we measured via laser fluorination δ18O values of groundmass and phenocrysts from Coso lavas erupted between 170 ka and 60 ka, as well as nearby Pleistocene (Big Pine & Kern Plateau) rhyolites and basalts. δ18O values of Coso groundmass obsidian and quartz phenocrysts range from 8.1 to 8.6‰ and 8.6 to 8.7‰, respectively, and are similar over the span of eruptive episodes. These values are similar to nearby high-silica rhyolites at Big Pine and Long Valley. The δ18O values of Coso rhyolites are too high to reflect simple fractionation of coeval contaminated basalt (olivine = 5.9‰); nominal mantle δ18O values (olivine) for the Owens Valley from primitive Big Pine basalt and lherzolite xenoliths are 5.3-5.6‰. The relatively high δ18O values for Coso rhyolites suggest recycling of crustal lithologies, which are locally dominated by Mesozoic granitoids. A significant crustal component in the Coso rhyolites is supported by the presence of abundant zircons that yield Mesozoic U-Pb ages. Kern Plateau basalts and rhyolites yield δ18O values that are somewhat elevated (up to 1‰) relative to Coso and Big Pine lavas, which suggest a relatively enriched mantle source but more likely indicate a greater crustal input from Sierra Nevadan crust. The similarity of δ18O values for Coso rhyolites erupted over an ~100 ka span of time suggests that the crustal source for the rhyolites has a restricted range of δ18O values and/or differentiation of the magma reservoir is effective at homogenizing the O

  19. Emergency Assessment of Debris-Flow Hazards from Basins Burned by the 2007 Slide and Grass Valley Fires, San Bernardino County, Southern California

    USGS Publications Warehouse

    Cannon, Susan H.; Gartner, Joseph E.; Michael, John A.; Bauer, Mark A.; Stitt, Susan C.; Knifong, Donna L.; McNamara, Bernard J.; Roque, Yvonne M.

    2007-01-01

    INTRODUCTION The objective of this report is to present a preliminary emergency assessment of the potential for debris-flow generation from basins burned by the Slide and Grass Valley Fires in San Bernardino County, southern California in 2007. Debris flows are among the most hazardous geologic phenomena; debris flows that followed wildfires in southern California in 2003 killed 16 people and caused tens of millions of dollars of property damage. A short period of even moderate rainfall on a burned watershed can lead to debris flows. Rainfall that is normally absorbed into hillslope soils can run off almost instantly after vegetation has been removed by wildfire. This causes much greater and more rapid runoff than is normal from creeks and drainage areas. Highly erodible soils in a burn scar allow flood waters to entrain large amounts of ash, mud, boulders, and unburned vegetation. Within the burned area and downstream, the force of rushing water, soil, and rock can destroy culverts, bridges, roadways, and buildings, potentially causing injury or death. This emergency debris-flow hazard assessment is presented as relative ranking of the predicted median volume of debris flows that can issue from basin outlets in response to 3.50 inches (88.90 mm) of rainfall over a 3-hour period. Such a storm has a 10-year return period. The calculation of debris flow volume is based on a multiple-regression statistical model that describes the median volume of material that can be expected from a recently burned basin as a function of the area burned at high and moderate severity, the basin area with slopes greater than or equal to 30 percent, and triggering storm rainfall. Cannon and others (2007) describe the methods used to generate the hazard maps. Identification of potential debris-flow hazards from burned drainage basins is necessary to issue warnings for specific basins, to make effective mitigation decisions, and to help plan evacuation timing and routes.

  20. Occurrence of Cryptosporidium and Giardia in wild ducks along the Rio Grande River valley in southern New Mexico.

    PubMed

    Kuhn, Ryan C; Rock, Channah M; Oshima, Kevin H

    2002-01-01

    Fecal samples were taken from wild ducks on the lower Rio Grande River around Las Cruces, N. Mex., from September 2000 to January 2001. Giardia cysts and Cryptosporidium oocysts were purified from 69 samples by sucrose enrichment followed by cesium chloride (CsCl) gradient centrifugation and were viewed via fluorescent-antibody (FA) staining. For some samples, recovered cysts and oocysts were further screened via PCR to determine the presence of Giardia lamblia and Crytosporidium parvum. The results of this study indicate that 49% of the ducks were carriers of Cryptosporidium, and the Cryptosporidium oocyst concentrations ranged from 0 to 2,182 oocysts per g of feces (mean +/- standard deviation, 47.53 +/- 270.3 oocysts per g); also, 28% of the ducks were positive for Giardia, and the Giardia cyst concentrations ranged from 0 to 29,293 cysts per g of feces (mean +/- standard deviation, 436 +/- 3,525.4 cysts per g). Of the 69 samples, only 14 had (oo)cyst concentrations that were above the PCR detection limit. Samples did test positive for Cryptosporidium sp. However, C. parvum and G. lamblia were not detected in any of the 14 samples tested by PCR. Ducks on their southern migration through southern New Mexico were positive for Cryptosporidium and Giardia as determined by FA staining, but C. parvum and G. lamblia were not detected.

  1. Paleomagnetic definition of crustal fragmentation and Quaternary block rotations in the east Ventura Basin and San Fernando valley, southern California

    NASA Astrophysics Data System (ADS)

    Levi, Shaul; Yeats, Robert S.

    2003-10-01

    Paleomagnetic studies of the Pliocene-Quaternary Saugus Formation in the eastern part of the western Transverse Ranges of California show that the crust is fragmented into small domains, tens of kilometers in linear dimension, identified by rotation of reverse-fault blocks. In an area approximately 35 × 25 km in the San Fernando valley and east Ventura Basin we identified four distinct domains. Two domains, southwest of and adjacent to the San Gabriel fault, are rotated clockwise: (1) The Magic Mountain domain, R = 30° ± 5° and (2) the Merrick syncline domain, R = 34° ± 6°. The Magic Mountain domain has rotated since 1 Ma. Both rotated sections occur in hanging walls of active reverse faults, the Santa Susana and San Fernando faults, respectively. Structural data suggest that the fault tip of the Santa Susana fault is the rotation pivot of the Magic Mountain domain. Two additional blocks are unrotated: (1) the Van Norman Lake domain, directly south of the Santa Susana fault, and (2) the Soledad Canyon domain, immediately across the San Gabriel fault from the Magic Mountain domain, suggesting that the San Gabriel fault might be a domain boundary. Our results suggest that part of the clockwise rotation of some Miocene and older rocks in this area might have occurred in the Quaternary. The Plio-Pleistocene fragmentation and clockwise rotations continue at present, based on geodetic data, and represent crustal response to diffuse, oblique dextral shearing within the San Andreas fault system.

  2. Subsurface geology of the late Tertiary and Quaternary water-bearing deposits of the southern part of the San Joaquin Valley, California

    USGS Publications Warehouse

    Croft, M.G.

    1972-01-01

    The study area, which includes about 5,000 square miles of the southern part of the San Joaquin Valley, is a broad structural trough of mostly interior drainage. The Sierra Nevada on the east is composed of consolidated igneous and metamorphic rocks of pre-Tertiary age. The surface of these rocks slopes 4?-6? southwestward from the foothills and underlies the valley. The Coast Ranges on the west consist mostly of complexly folded and faulted consolidated marine and nonmarine sedimentary rocks of Jurassic, Cretaceous, and Tertiary age, which dip eastward and overlie the basement complex. Unconsolidated deposits, of late Pliocene to Holocene age, blanket the underlying consolidated rocks in the valley and are the source of most of the fresh ground water. The unconsolidated deposits, the subject of this report, are divided into informal stratigraphic units on the basis of source of sediment, environment of deposition, and texture. Flood-basin, lacustrine, and marsh deposits are fine grained and underlie the valley trough. They range in age from late Pliocene to Holocene. These deposits, consisting of nearly impermeable gypsiferous fine sand, silt, and clay, are more than 3,000 feet thick beneath parts of Tulare Lake bed. In other parts of the trough, flood-basin, lacustrine, and marsh deposits branch into clayey or silty clay tongues designated by the letter symbols A to F. Three of these tongues, the E, C, and A clays, lie beneath large areas of the southern part of the valley. The E clay includes the Corcoran Clay Member of the Tulare Formation, the most extensive hydrologic confining layer in the valley. The E clay underlies about 3,500 square miles of bottom land and western slopes. The beds generally are dark-greenish-gray mostly diatomaceous silty clay of Pleistocene age. Marginally, the unit bifurcates into an upper and a lower stratum that contains thin beds of moderately yellowish-brown silt and sand. The E clay is warped into broad, gentle northwesterly

  3. Geodetic Constraints on the Rigidity and Eastern Boundary of the Sierra Nevada Micro-Plate, from Mohawk Valley to Southern Walker Lane

    NASA Astrophysics Data System (ADS)

    Kreemer, C. W.; Hammond, W. C.; Blewitt, G.

    2009-12-01

    The Sierra Nevada - Great Valley (SNGV) micro-plate has long been recognized as a tectonically rigid, though mobile, entity within the Pacific - North America plate boundary zone. The motion of the SNGV relative to stable North America (and the Colorado Plateau) provides the kinematic boundary condition for, and perhaps drives, the deformation in the Basin and Range Province (BRP) and Walker Lane. In the north the motion of the SNGV is aligned with the Mohawk Valley fault zone, which could have a slip rate of over a few mm/yr. The crest of the Sierras marks the SNGV’s eastern edge, but the obliquity between orientation of this boundary and the block’s motion implies an expected increase in rangefront-normal extension from the northern to southern Walker Lane. We use new GPS data from the EarthScope Plate Boundary Observatory (PBO) and our own semi-continuous MAGNET network to revisit the following questions: 1) Do the data still support rigidity of the SNGV?; 2) How far east does the rigidity extend and how does this relate to SNGV lithology?; 3) How does the direction of SNGV motion relate to the strike of its eastern margin and observed strain partitioning (and its along strike variation) in the Walker Lane?; and 4) How is SNGV-BRP motion accommodated between the Walker Lane and the Cascadia forearc? We analyze data from all the available continuous GPS sites in the greater SNGV region, including new data from PBO, as well as data from MAGNET. All data are processed with the GIPSY-OASIS II precise point positioning software using recently reprocessed orbits from JPL's IGS Analysis Center. The processing includes satellite and station antenna calibrations and all data have the phase ambiguities fixed using the Ambizap algorithm. Positions are estimated in our custom-made North America reference frame in which continental-scale common-mode errors are removed. Velocities and uncertainties are estimated using the CATS software in which we assuming an error model

  4. Mechanics of Alleghenian emplacement of thrust sheets along the Blue Ridge-Valley and Ridge boundary in the Southern Appalachians

    SciTech Connect

    Bartholomew, M.J.

    1985-01-01

    The structural interaction between emplacement of the crystalline Blue Ridge thrust sheet (BRTS) and associated Alleghenian deformation in the Valley and Ridge can be, in part, deduced from the deformational style and sequence found in the structurally underlying Pulaski thrust sheet (PTS). Within the PTS both crosscutting and superimposed structural relationships indicate that Alleghenian deformation proceeded through 5 distinct stages involving the PTS. Structures formed during: stage A- as the BRTS ascended a footwall ramp over the PTS and the major lower level decollement zone (LLDZ) in Cambrian strata formed at the base of the PTS; stage B- as the coupled BRTS-PTS ascended a footwall ramp across Cambrian through middle Ordovician strata; stage C- as the PTS crossed the upper Ordovician through Devonian portion of that ramp; stage D- as the BRTS-PTS crossed upper Devonian and Mississippian rocks and reached the upper level decollement zone in Mississippian strata; stage E- post BRTS-PTS emplacement. Stage A was characterized by development of both an imbricate fan in the Rome Formation beneath the BRTS and a thick LLDZ containing abundant tectonic breccia near the Rome/Elbrook contact. The upper bounding surface (UBS) of this LLDZ is folded by broad folds and cut by faults formed during later stages as footwall tectonic slices were incorporated into the base of the PTS. Thus, regional fold and fault trends and relationships with the UBS suggest that most of the complex deformation and tectonic breccia found within the LLDZ formed prior to the PTS ascending the footwall ramp.

  5. Climate History of the Southern San Joaquin Valley of California, USA: Authentic Paleoclimate Research with K-12 Teachers

    NASA Astrophysics Data System (ADS)

    Baron, D.; Negrini, R. M.; Palacios-Fest, M. R.; Auffant, K.

    2006-12-01

    For three summers, the Department of Geology at California State University, Bakersfield (CSUB) has invited teachers from local schools to participate in a research program that is investigating the climate history of the San Joaquin Valley of California. In each 4-week summer project, three elementary/middle school teachers and three high school teachers worked with CSUB faculty, undergraduate geology students, and a small group of high school students. The research centers around the analysis of 50-foot (15 m) sediment cores from two locations in the Tulare Lake basin. These cores preserve a regional climate record dating back to about 35,000 years before the present. Research tasks include the description of sediments from the cores for parameters such as grain size, color, and mineralogy. Sediment analyses include total organic and total inorganic carbon, as well as magnetic susceptibility. Ostracode shells were separated from the sediments, ostracode species present were identified and their abundances determined. Each teacher was put in charge of the description and analysis of several 5-foot (1.5 m) core segments. Each teacher was the leader of a research group including a CSUB geology student and one or two high school students. The groups were responsible for all aspects of the description and analysis of their core segments. They were also in charge of the paleoclimate interpretations and the presentation of their research results at the end of the summer projects. Surveys conducted before and after the summer program indicate that teacher's knowledge of climate change and regional geology, as well as their confidence in teaching Earth science at their schools increased. Follow- up surveys conducted a year after the first summer program indicate that the research experience had a lasting positive impact on teacher's confidence and their enthusiasm for teaching Earth science. Several of the teachers have developed lesson plans and/or field trips for their

  6. Hydrogeological aspects and environmental concerns of the New Valley Project, Western Desert, Egypt, with special emphasis on the southern area

    NASA Astrophysics Data System (ADS)

    Assaad, Fakhry A.

    1988-12-01

    The New Valley Project has been given much attention in the past 20 years especially from the hydrogeological point of view concerning groundwater utilization for the reclamation of a large area of the Western Desert. Lithological, petrophysical, and petrographical studies were conducted on four wells south of Beris Oasis, namely Beris 20, Beris 15, Beris 14, and Beris 13, and are defined by latitudes 24°25'E and 24°35'E and longitudes 30°30'N and 30°46'N. The Nubian sedimentation is of Posttectonic deposition that took place over the uplifted Precambrian granitic basement and is Lower Cretaceous, whereas the upper most variegated shales of the cap rock are Upper Cretaceous. The Nubian sandstones in the area south of Beris Oasis contain hematitic stains and/or fine granular authigenic hematite, thin laminae of brown ferruginous quartzite is also recorded denoting oxidizing conditions in the basin of deposition. Thin streaks of carbonaceous shales are met with in different depths to the south of Beris area, may be taken to denote oscillations in the sea level and accordingly its depths, and are responsible for the change in the oxidation-reduction potential during the deposition of the corresponding beds. Lithologic logs were interpreted together with the electric and micro-logs for adjustment of the shale breaks and showed that there are five water-bearing zones, named from bottom to top: A, B, C, D, and E, and are mainly unfossiliferous orthoquartzites, separated from each other by impervious beds of siltstones, shales, and clays of varying thicknesses. This zoning had been found valid in other parts of the Kharga Oases and could be applied locally in the Kharga Oases area. Mechanical analysis was performed mainly on 39 samples, of which 18 were core samples and 21 were cuttings, that were raised from four wells dug in the area south of Beris Oasis, Kharga Oases. Porosity and permeability tests were carried out on the 18 core samples only. The implication of

  7. Electrical resistivity imaging (ERI) and ground-penetrating radar (GPR) survey at the Giribaile site (upper Guadalquivir valley; southern Spain)

    NASA Astrophysics Data System (ADS)

    Martínez, J.; Rey, J.; Gutiérrez, L. M.; Novo, A.; Ortiz, A. J.; Alejo, M.; Galdón, J. M.

    2015-12-01

    The Giribaile archaeological site is one of the most important Iberian enclaves of the Alto Guadalquivir (Southern Spain). However, to date, only minimal excavation work has been performed at the site. Evaluation requires a preliminary, non-destructive general analysis to determine high-interest areas. This stage required a geophysical survey. Specifically, a 100 m2 grid was selected, where an initial campaign of nine electrical resistivity imaging (ERI) profiles was performed, where each profile was 111 m in length; these profiles were previously located using a detailed topographical survey. A total of 112 electrodes were used for each profile, spaced at 1 m apart with a Wenner-Schlumberger configuration. Secondly, 201 GPR profiles were created using a 500 MHz antenna. The 100 m long profiles were spaced 0.5 m apart and parallel to one another. The present research analyses the efficiency of each of these geophysical tools in supporting archaeological research. Using these methodologies, the position, morphology, and depth of different buried structures can be determined. 3D interpretation of the geophysical survey in 100 × 100 m grid allowed to differentiate structures square and rectangular, interesting buildings in a semicircle (interpreted as ovens) plus delineate different streets. From the geophysical survey follows the Carthaginian presence inside this ancient Iberian enclave.

  8. Holocene planform change in broad valleys in the Southern Rocky Mountains: the role of vegetation type and beaver in shaping long-term channel complexity

    NASA Astrophysics Data System (ADS)

    Polvi-Pilgrim, L. E.; Wohl, E.

    2012-04-01

    Over the past decade, researchers have shown the importance of streambank vegetation in forming meandering channels. Recent work has also showed the importance of beaver in creating a more heterogeneous landscape, in terms of channel planform and complexity, sedimentation, and riparian vegetation. Streambank vegetation and beavers interact as ecosystem engineers to determine long-term channel planform, floodplain processes, and complexity. We use studies of Holocene beaver aggradation and effects on channel complexity, in addition to measurements of added bank strength by various riparian vegetation types, to predict Holocene planform change in broad (>200 m, disconnected from hillslopes), high-elevation (>2300 m) valleys of the Colorado Front Range in the Southern Rocky Mountains. Sediment core analyses and shallow subsurface geophysical measurements indicate that post-glacial beaver-related aggradation is significant. Additionally, historical and field evidence from the last century, when the beaver population steadily declined, shows that beaver contribute to the formation of a complex, multi-thread channel network. Streambank vegetation in the Colorado Front Range can be categorized based on its ability to provide added strength to the streambank, where riparian or rhizomatous shrubs and trees provide more strength than xeric trees or non-rhizomatous graminoids and herbs, depending on the bank texture and hydrologic conditions. Assuming a snowmelt-dominated flow regime in a gravel-bed channel system, four planform regimes are identified based on beaver populations and the abundance and presence of xeric or riparian vegetation. Following deglaciation, without beaver or bank-stabilizing vegetation, (1) a braided channel formed. The introduction of riparian vegetation and a more stable flow regime triggered a transition to (2) a meandering channel, which in turn provided habitat for beaver, allowing the formation of (3) a complex multi-thread channel system. The

  9. Analysis of particulate matter in anthropized areas characterized by the presence of crude oil pre-treatment plants: The case study of the Agri Valley (Southern Italy)

    NASA Astrophysics Data System (ADS)

    Trippetta, Serena; Caggiano, Rosa; Telesca, Luciano

    2013-10-01

    Simultaneous measurements of PM10, PM2.5 and PM1 (i.e., aerosol particles with aerodynamic diameter less than 10, 2.5 and 1 μm, respectively) daily mass concentrations and daily particle number concentration were performed for the first time in Agri Valley (Basilicata Region - Southern Italy) from July to November 2011. This area is characterized by anthropogenic activities having high potential environmental and human health impacts. In fact, the Agri Valley houses the largest European on-shore reservoir and the largest crude oil pre-treatment plant within an anthropized area. The PM measurements were analyzed combining an innovative statistical methodology, the Singular Spectral Analysis, with forecast models and remote sensing observations. Our findings show that most of the PM collected was made up of particles in the fine and sub-micrometric fractions (i.e., PM2.5 and PM1, respectively) very likely originated by common anthropogenic sources. Moreover, PM2.5 and PM1 daily mass concentrations were characterized by a slightly increasing trend that could be related to the contribution of local sources, such as the crude oil pre-treatment plant, whose combustion processes also produce the emission of particles mainly in the fine and sub-micrometric size ranges. The integrated use of model forecasts, satellite observations and in-situ measurements shows that the only PM10 exceedance was affected by the contribution of Saharan dust, while the three PM2.5 exceedances were mainly due to local anthropogenic sources. Finally, the analysis of the PM10 and PM2.5 Air Quality Index (AQI) values shows that air quality was always “good” with respect to PM10 and “moderate” with respect to PM2.5 suggesting that fine particles, if they will be not kept under control, should represent a real problem also posing health risks to the population living close to the crude oil pre-treatment plant.

  10. Effects of source rocks, soil features and climate on natural gamma radioactivity in the Crati valley (Calabria, Southern Italy).

    PubMed

    Guagliardi, Ilaria; Rovella, Natalia; Apollaro, Carmine; Bloise, Andrea; De Rosa, Rosanna; Scarciglia, Fabio; Buttafuoco, Gabriele

    2016-05-01

    The study, which represents an innovative scientific strategy to approach the study of natural radioactivity in terms of spatial and temporal variability, was aimed to characterize the background levels of natural radionuclides in soil and rock in the urban and peri-urban soil of a southern Italy area; to quantify their variations due to radionuclide bearing minerals and soil properties, taking into account nature and extent of seasonality influence. Its main novelty is taking into account the effect of climate in controlling natural gamma radioactivity as well as analysing soil radioactivity in terms of soil properties and pedogenetic processes. In different bedrocks and soils, activities of natural radionuclides ((238)U, (232)Th (4) K) and total radioactivity were measured at 181 locations by means of scintillation γ-ray spectrometry. In addition, selected rocks samples were collected and analysed, using a Scanning Electron Microscope (SEM) equipped with an Energy Dispersive Spectrometer (EDS) and an X-Ray Powder Diffraction (XRPD), to assess the main sources of radionuclides. The natural-gamma background is intimately related to differing petrologic features of crystalline source rocks and to peculiar pedogenetic features and processes. The radioactivity survey was conducted during two different seasons with marked changes in the main climatic characteristics, namely dry summer and moist winter, to evaluate possible effects of seasonal climatic variations and soil properties on radioactivity measurements. Seasonal variations of radionuclides activities show their peak values in summer. The activities of (238)U, (232)Th and (4) K exhibit a positive correlation with the air temperature and are negatively correlated with precipitations.

  11. Long-Term Land Cover and Land Use Change Detection in the Kilombero Floodplain (Tanzania) Using Multitemporal Metrics-Based Compositing

    NASA Astrophysics Data System (ADS)

    Thonfeld, Frank; Amler, Esther; Kirimi, Fridah; Steinbach, Stefanie; Menz, Gunter

    2016-08-01

    Land cover and land use changes have great impact on the hydrological characteristics of the Kilombero floodplain wetland (Tanzania) and its surroundings. Conservation interests meet the wetland's ecosystem function as a site for growing food production. The system, processes and ecosystem responses are, however, not yet fully understood. We make use of Landsat data to assess long-term land cover and land use changes in the catchment. In this paper we describe an approach to circumvent the challenge of frequent cloud cover and to consider the dynamics of the wetland during the classification. The approach results in temporal composites for four different decades and hierarchically organized maps including two levels of detail and providing information about dynamic classes.

  12. Reconnaissance investigation of water quality, bottom sediment, and biota associated with irrigation drainage in the Tulare Lake bed area, southern San Joaquin Valley, California, 1986-87

    USGS Publications Warehouse

    Schroeder, R.A.; Palawski, D.U.; Skorupa, J.P.

    1988-01-01

    Concentrations of numerous toxic trace elements and pesticides were measured during 1986 in water, sediment, and biota from three areas near the Tulare Lake Bed, southern San Joaquin Valley, California: Kern National Wildlife Refuge, Pixley National Wildlife Refuge, and Westfarmers evaporation ponds about 5 mi west of Kern National Wildlife Refuge, to determine whether toxic constituents in agricultural-irrigation drainage pose a threat to beneficial uses of water, especially to uses by wildlife. Pesticide residues were found to be low at all three areas. Trace element concentrations were found to be comparatively low at the Kern and Pixley National Wildlife Refuge areas and high at the Westfarmers evaporation ponds. Dissolved selenium concentrations were < 1 micrograms/L (ug/L) in areas on and adjacent to the refuges, but ranged from 110 to 360 ug/L in the saline drainwater impounded in the evaporation ponds. The ratio of mean selenium concentrations in biota from Westfarmers ponds compared to biota from Kesterson National Wildlife Refuge (where adverse effects have been documented) is 5 for waterboatman, 2 for avocet liver, 1 for avocet eggs, and < 1 for widgeongrass. The low concentrations measured at Kern and Pixley National Wildlife Refuges suggest that trace elements and pesticides pose little threat to wildlife there; however, impounded subsurface drainage from agricultural irrigation does pose a threat to wildlife at the nearby Westfarmers ponds. Preliminary results of surveys conducted in 1987 indicated that there are adverse biological effects on shorebirds nesting at the ponds, although interpretation of the magnitude of the effects is premature, pending completion of ongoing studies by the U.S. Fish and Wildlife Service. (Author 's abstract)

  13. Status and understanding of groundwater quality in the two southern San Joaquin Valley study units, 2005-2006 - California GAMA Priority Basin Project

    USGS Publications Warehouse

    Burton, Carmen A.; Shelton, Jennifer L.; Belitz, Kenneth

    2012-01-01

    Groundwater quality in the southern San Joaquin Valley was investigated from October 2005 through March 2006 as part of the Priority Basin Project of the Groundwater Ambient Monitoring and Assessment (GAMA) Program. The GAMA Priority Basin Project is conducted by the U.S. Geological Survey (USGS) in collaboration with the California State Water Resources Control Board and the Lawrence Livermore National Laboratory. There are two study units located in the southern San Joaquin Valley: the Southeast San Joaquin Valley (SESJ) study unit and the Kern County Subbasin (KERN) study unit. The GAMA Priority Basin Project in the SESJ and KERN study units was designed to provide a statistically unbiased, spatially distributed assessment of untreated groundwater quality within the primary aquifers. The status assessment is based on water-quality and ancillary data collected in 2005 and 2006 by the USGS from 130 wells on a spatially distributed grid, and water-quality data from the California Department of Public Health (CDPH) database. Data was collected from an additional 19 wells for the understanding assessment. The aquifer systems (hereinafter referred to as primary aquifers) were defined as that part of the aquifer corresponding to the perforation interval of wells listed in the CDPH database for the SESJ and KERN study units. The status assessment of groundwater quality used data from samples analyzed for anthropogenic constituents such as volatile organic compounds (VOCs) and pesticides, as well as naturally occurring inorganic constituents such as major ions and trace elements. The status assessment is intended to characterize the quality of untreated groundwater resources within the primary aquifers in the SESJ and KERN study units, not the quality of drinking water delivered to consumers. Although the status assessment applies to untreated groundwater, Federal and California regulatory and non-regulatory water-quality benchmarks that apply to drinking water are used

  14. Sources, trends and regional impacts of fine particulate matter in southern Mississippi Valley: significance of emissions from sources in the Gulf of Mexico coast

    NASA Astrophysics Data System (ADS)

    Chalbot, M.-C.; McElroy, B.; Kavouras, I. G.

    2013-01-01

    The sources of fine particles over a 10 yr period at Little Rock, Arkansas, an urban area in southern Mississippi Valley, were identified by positive matrix factorization. The annual trends of PM2.5 and its sources and their associations with the pathways of air mass backward trajectories were examined. Seven sources were apportioned, namely, primary traffic particles, secondary nitrate and sulphate, biomass burning, diesel particles, aged/contaminated sea salt and mineral/road dust, accounting for more than 90% of measured PM2.5 mass. The declining trend of PM2.5 mass (0.4 μg m-3 yr-1) was related to lower levels of SO42- (0.2 μg m-3 yr-1) due to SO2 reductions from point and mobile sources. The slower decline for NO3- particles (0.1 μg m-3 yr-1) was attributed to the spatial variability of NH3 in Midwest. The annual variation of biomass burning particles was associated with wildland fires in southeast and northwest US that are sensitive to climate changes. The four regions within 500 km from the receptor site, the Gulf Coast and southeast US accounted cumulatively for more than 65% of PM2.5 mass, nitrate, sulphate and biomass burning aerosol. Overall, more than 50% of PM2.5 and its sources originated from sources outside the state. Sources within the Gulf Coast and western Gulf of Mexico include 65% of the busiest ports in the US, intense marine traffic within 400 km of the coast burning rich in S diesel, and a large number of offshore oil and natural gas platforms and many refineries along the coast. This approach allowed for quantitatively assessing the impacts of transport from regions representing diverse mixtures of sources and weather conditions for different types of particles. The findings of this effort demonstrated the influences of emission controls on SO2 and NOx on PM2.5 mass, the potential effect of events (i.e. fires) sensitive to climate change phenomena on air pollution and the potential of offshore activities and shipping emissions to

  15. Natural selection and type 2 diabetes-associated mortality in an isolated indigenous community in the valley of Oaxaca, southern Mexico.

    PubMed

    Little, Bertis B; Peña Reyes, Maria Eugenia; Malina, Robert M

    2017-03-01

    This study tests the hypothesis that natural selection is associated with type 2 diabetes (T2D)-associated mortality and fertility in a rural isolated Zapotec community in the Valley of Oaxaca, southern Mexico. Mortality data and related demographic and genealogic information were linked with data for fertility, prereproductive mortality and family history of mortality attributed to T2D. Physician verified T2D mortality (n = 27) between 1980 and 2009 and imputed T2D (n = 70) from cardiovascular mortality (68% random sample) and renal failure (44% random sample). Bootstrapping was used to obtain a robust variance estimate in survival analysis and multivariate analysis of variance. Estimated maximum natural selection by Crow's Index occurred circa 1930 and was relaxed after this time in the study population. Cox-regression survival analysis of T2D mortality with covariates (family history of T2D, cardiovascular disease, renal failure) indicated a significant hazard ratio (HR = 5.95, 95% CI: 1.38-25.67, p < .008) for the increase in T2D in 2000 to 2009. Survival analysis of imputed T2D resulted in a significant HR of 2.03 (95% CI: 1.08-3.85, p = .01) for the increase in T2D in the 2000 to 2009 cohort (reference group: 1980-1989). Mean number of live born offspring was lower among T2D (n = 27, 4.04 ± 3.85 SD) compared to non-T2D (n = 199, 5.30 ± 3.48) groups (p < .08). Mean number of live born offspring was lower (p = .003) among imputed T2D compared to non-T2D groups (4.10 ± 3.44 vs. 5.62 + 3.50). T2D-associated mortality increased in frequency as natural selection decreased, and favored offspring survival of non-T2D descedants. The results indicated statistically significant directional selection against T2D and imputed T2D to this population isolate. © 2016 Wiley Periodicals, Inc.

  16. Sources, trends and regional impacts of fine particulate matter in southern Mississippi valley: significance of emissions from sources in the Gulf of Mexico coast

    NASA Astrophysics Data System (ADS)

    Chalbot, M.-C.; McElroy, B.; Kavouras, I. G.

    2013-04-01

    The sources of fine particles over a 10 yr period at Little Rock, Arkansas, an urban area in the southern Mississippi Valley, were identified by positive matrix factorization. The annual trends of PM2.5 and its sources, and their associations with the pathways of air mass backward trajectories were examined. Seven sources were apportioned, namely, primary traffic particles, secondary nitrate and sulphate, biomass burning, diesel particles, aged/contaminated sea salt and mineral/road dust, accounting for more than 90% of measured PM2.5 (particles with aerodynamic diameter less than 2.5 μm) mass. The declining trend of PM2.5 mass (0.4 μg m-3 per year) was related to lower levels of SO42- (0.2 μg m-3 per year) due to SO2 reductions from point and mobile sources. The slower decline for NO3- particles (0.1 μg m-3 per year) was attributed to the increasing NH3 emissions in the Midwest. The annual variation of biomass burning particles was associated with fires in the southeast and northwest US. Of the four regions within 500 km from the receptor site, the Gulf Coast and the southeast US accounted cumulatively for more than 65% of PM2.5 mass, nitrate, sulphate and biomass burning aerosol. Overall, more than 50% of PM2.5 and its components originated from sources outside the state. Sources within the Gulf Coast and western Gulf of Mexico include 65% of the busiest ports in the US, intense marine traffic within 400 km of the coast burning rich in S diesel, and a large number of offshore oil and natural gas platforms and many refineries. This approach allowed for the quantitative assessment of the impacts of transport from regions representing diverse mixtures of sources and weather conditions for different types of particles. The findings of this effort demonstrated the influences of emission controls on SO2 and NOx on PM2.5 mass, the potential effect of events (i.e. fires) sensitive to climate change phenomena on air pollution and the potential of offshore activities

  17. Introduction and establishment of tadpole shrimp Triops newberryi (Notostraca: Triopsidae) in a date garden for biological control of mosquitoes in the Coachella Valley, Southern California.

    PubMed

    Su, Tianyun; Mulla, Mir S

    2002-06-01

    Tadpole shrimp (TPS), Triops newberryi (Packard), has been reported to have a potential as a biocontrol agent for larval mosquitoes breeding in intermittently flooded habitats. To develop and promote this predator for controlling mosquitoes, a date garden devoid of preexisting TPS populations was chosen in the Coachella Valley, southern California in 2000 to receive introductions of TPS eggs and mature TPS. Mosquito control by TPS was assessed in the plots one year after their introductions. In a selected block on this ranch, 2 rows were stocked with TPS eggs, where soil containing approximately 2,000 eggs was spread over the surface of dry ground in each row before flooding. Another 2 rows were used for mature TPS introduction, where about 400 mature TPS were released into standing water in each row 1 day after flooding. After a single egg or mature TPS introduction, active TPS in water and viable eggs in dry surface soil were noted in increasing numbers during the 3-4 subsequent irrigations. Disking before irrigation, which turned the eggs over and mixed them into the soil column, reduced TPS egg populations at the soil surface and subsequent active TPS populations in standing water after irrigation. After one or two irrigations, viable eggs and active shrimp were found in centers adjacent to the introduced plots in the stocked rows. Ample evidence is presented to show that TPS populations were established after a single introduction of eggs or mature TPS. TPS eggs and/or newly hatched TPS were also carried into the neighboring rows across the borders by the overflowing irrigation water, and TPS populations became established there too, as active TPS were noted after each irrigation in the adjacent unstocked rows. Considering the ease and economical storage, transportation and handling, dessication--resistant eggs have advantages over mature TPS for field introductions. Mosquito control by TPS was assessed in rows with and without TPS in July 2001, one year after

  18. Timing, Duration, and Effects of Droughts in the Southern Sierra Nevada and San Joaquin Valley, CA Over the Last 2000 Years

    NASA Astrophysics Data System (ADS)

    Adams, K. D.; Negrini, R. M.; Rajagopal, S.; Cook, E. R.

    2015-12-01

    The Central Valley of California is one of the most prolific agricultural areas in the U.S., providing about 25 % of the nation's food. This system is reliant on winter snows in the Sierra Nevada that gradually melt through the spring, but over the last 4 years California has been in the grip of its worst drought of the last 150 years. The question remains, however, how unusual is this drought when compared to previous events over longer time scales? We used moisture sensitive tree-ring chronologies from the Living Blended Drought Atlas of Cook et al. (2010) to reconstruct annual discharges over the last 2000 years for the Kings, Kaweah, Tule, and Kern rivers in the southern Sierra and routed this discharge into a Tulare Lake water balance model to simulate lake-level fluctuations over this same time period. Although the current drought represents the driest consecutive four year period over the past 2000 years, in terms of discharge volumes, there are multiple periods of more severe, longer term drought represented by extended periods of low lake levels. Significant low-lake periods (< 61 m) include 793-814, 906-933, and 1140-1158, all of which occurred during the Medieval Climate Anomaly. Conversely, lake levels were predominately high during the ensuing Little Ice Age, separated by brief periods of low lake levels. Under natural flow conditions, the 1923-1935 drought would have lowered lake level to about 58 m, which is about 2 m lower than where lake level would have been in the current drought. Wavelet analyses of the streamflow and lake-level records reveal different periodicities of drought and wet conditions because lake-level is a state variable that changes relatively slowly, depending on inflow, precipitation on the lake, evaporation rate, and the hypsometry of the basin, whereas streamflow is a flux that responds immediately to climate perturbations. The streamflow records have a dominant period of 2-8 yrs but lake-level fluctuations follow longer

  19. Decreased availability of antimalarials in the private sector following the policy change from chloroquine to sulphadoxine-pyrimethamine in the Kilombero Valley, Tanzania

    PubMed Central

    Hetzel, Manuel W; Msechu, June J; Goodman, Catherine; Lengeler, Christian; Obrist, Brigit; Kachur, S Patrick; Makemba, Ahmed; Nathan, Rose; Schulze, Alexander; Mshinda, Hassan

    2006-01-01

    Background Malaria control strategies emphasize the need for prompt and effective treatment of malaria episodes. To increase treatment efficacy, Tanzania changed its first-line treatment from chloroquine to sulphadoxine-pyrimethamine (SP) in 2001. The effect of this policy change on the availability of antimalarials was studied in rural south-eastern Tanzania. Methods In 2001 and 2004, the study area was searched for commercial outlets selling drugs and their stocks were recorded. Household information was obtained from the local Demographic Surveillance System. Results From 2001 to 2004, the number of general shops stocking drugs increased by 15% and the number of drug stores nearly doubled. However, the proportion of general shops stocking antimalarials dropped markedly, resulting in an almost 50% decrease of antimalarial selling outlets. This led to more households being located farther from a treatment source. In 2004, five out of 25 studied villages with a total population of 13,506 (18%) had neither a health facility, nor a shop as source of malaria treatment. Conclusion While the change to SP resulted in a higher treatment efficacy, it also led to a decreased antimalarial availability in the study area. Although there was no apparent impact on overall antimalarial use, the decline in access may have disproportionately affected the poorest and most remote groups. In view of the imminent policy change to artemisinin-based combination therapy these issues need to be addressed urgently if the benefits of this new class of antimalarials are to be extended to the whole population. PMID:17105662

  20. How a geology map of the Upper Santa Maria Valley in the Southern Swiss Alps played a critical role in solving a hydrogeologic enigma

    NASA Astrophysics Data System (ADS)

    Otz, M. H.; Otz, I.

    2010-12-01

    Several regional-scale, fluorescent dye-tracing tests recently showed counter-intuitive, tectonically influenced, preferential ground water flow from the Piora Region via the Santa Maria Valley to the di Campo Valley. Losing rivers of the Piora Valley recharge the Triassic Piora Aquifer at an average rate of 20,000 m3/d and hydrologic budgets suggest that half of the Upper Santa Maria discharge originates from the Piora Region. The geologic map of the Upper Santa Maria Valley presented a partial solution to the hydrogeologic puzzle of the Piora Aquifer, thus facilitating construction of the AlpTransit railway tunnel (the longest on Earth). The autochthonous Lucomagno Triassic of the Gotthard Massif (cargneules), the allochthonous Frodalera-Peiden Triassic (sugar dolomites, para-gneises, quartzites, green phyllites), the Stgir Series of the Lower Jurassic (sandy limestones and quartzites), the Inferno Series of the Middle Jurassic (coarse sandstones, limestones, shales), the Coroi Series of the Upper Jurassic (black shales), the crystalline Gotthard Massif (ortho-gneises), and the northern Penninic Nappe (para- and ortho-gneises, quartzites) are the main lithologies found in the outcrops of the Upper Santa Maria Valley. The highly weathered Triassic series found in the Piora and Upper Santa Maria Valley posed a potential hydrogeologic obstacle that was overcome by tunnel drillers in early 2010, for expected tunnel service by 2012.

  1. East African Rift Valley, Kenya

    NASA Technical Reports Server (NTRS)

    1990-01-01

    This rare, cloud free view of the East African Rift Valley, Kenya (1.5N, 35.5E) shows a clear view of the Turkwell River Valley, an offshoot of the African REift System. The East African Rift is part of a vast plate fracture which extends from southern Turkey, through the Red Sea, East Africa and into Mozambique. Dark green patches of forests are seen along the rift margin and tea plantations occupy the cooler higher ground.

  2. East African Rift Valley, Kenya

    NASA Technical Reports Server (NTRS)

    1990-01-01

    This rare, cloud free view of the East African Rift Valley, Kenya (1.5N, 35.5E) shows a clear view of the Turkwell River Valley, an offshoot of the African REift System. The East African Rift is part of a vast plate fracture which extends from southern Turkey, through the Red Sea, East Africa and into Mozambique. Dark green patches of forests are seen along the rift margin and tea plantations occupy the cooler higher ground.

  3. A stacked Late Quaternary fluvio-periglacial sequence from the Axe valley, southern England with implications for landscape evolution and Palaeolithic archaeology

    NASA Astrophysics Data System (ADS)

    Brown, A. G.; Basell, L. S.; Toms, P. S.

    2015-05-01

    The current model of mid-latitude late Quaternary terrace sequences, is that they are uplift-driven but climatically controlled terrace staircases, relating to both regional-scale crustal and tectonic factors, and palaeohydrological variations forced by quasi-cyclic climatic conditions in the 100 K world (post Mid Pleistocene Transition). This model appears to hold for the majority of the river valleys draining into the English Channel which exhibit 8-15 terrace levels over approximately 60-100 m of altitudinal elevation. However, one valley, the Axe, has only one major morphological terrace and has long-been regarded as anomalous. This paper uses both conventional and novel stratigraphical methods (digital granulometry and terrestrial laser scanning) to show that this terrace is a stacked sedimentary sequence of 20-30 m thickness with a quasi-continuous (i.e. with hiatuses) pulsed, record of fluvial and periglacial sedimentation over at least the last 300-400 K yrs as determined principally by OSL dating of the upper two thirds of the sequence. Since uplift has been regional, there is no evidence of anomalous neotectonics, and climatic history must be comparable to the adjacent catchments (both of which have staircase sequences) a catchment-specific mechanism is required. The Axe is the only valley in North West Europe incised entirely into the near-horizontally bedded chert (crypto-crystalline quartz) and sand-rich Lower Cretaceous rocks creating a buried valley. Mapping of the valley slopes has identified many large landslide scars associated with past and present springs. It is proposed that these are thaw-slump scars and represent large hill-slope failures caused by Vauclausian water pressures and hydraulic fracturing of the chert during rapid permafrost melting. A simple 1D model of this thermokarstic process is used to explore this mechanism, and it is proposed that the resultant anomalously high input of chert and sand into the valley during terminations

  4. Fossil fuel burning in Taylor Valley, southern Victoria Land, Antarctica: Estimating the role of scientific activities on carbon and nitrogen reservoirs and fluxes

    SciTech Connect

    Lyons, W.B.; Nezat, C.A.; Welch, K.A.; Kottmeier, S.T.; Doran, P.T.

    2000-05-01

    Particulate organic and elemental carbon and nitrogen as well as NO{sub x} fluxes from scientific activities have been computed for Taylor Valley, Antarctica ({approximately}78{degree} S). These authropogenic fluxes have been compared to both the natural fluxes and landscape reservoirs as determined from Long-Term Ecological Research (LTER) investigations in the valley. The anthropogenic, nongaseous carbon fluxes are minor compared to the natural fluxes, while the anthropogenic NO{sub x} flux may be potentially important over decadal time scales.

  5. Selenium in ecosystems within the mountaintop coal mining and valley-fill region of southern West Virginia-assessment and ecosystem-scale modeling

    USGS Publications Warehouse

    Presser, Theresa S.

    2013-01-01

    Investigating the presence and variability of prey and predator species in demographically open systems such as streams also is key to model outcomes given the overall environmental stressors (for example, general landscape change, food-web disruption, recolonization potential) imposed on the composition of biological communities in coal mining and valley-fill affected watersheds

  6. Fault tectonics and earthquake hazards in the Peninsular Ranges, Southern California. [including San Diego River, Otay Mts., Japatul Valley, Barrett Lake, Horsethief Canyon, Pine Valley Creek, Pine Creek, and Mojave Desert

    NASA Technical Reports Server (NTRS)

    Merifield, P. M. (Principal Investigator)

    1975-01-01

    The author has identified the following significant results. Thin sections of rock exposed along the San Diego River linear were prepared and determined to be fault breccia. Single band and ratio images of the western Mojave Desert were prepared from the multispectral scanner digital tapes. Subtle differences in color of soil and rock are enhanced on the ratio images. Two north-northeast trending linears (Horsethief Canyon and Pine Valley Creek) and an east-west linear (Pine Creek) were concluded to have resulted from erosion along well-developed foliation in crystalline basement rocks.

  7. Southern cascades bioregion

    Treesearch

    Carl N. Skinner; Alan H. Taylor

    2006-01-01

    The Cascade Range extends from British Columbia, Canada, south to northern California where it meets the Sierra Nevada. The Southern Cascades bioregion in California is bounded on the west by the Sacramento Valley and the Klamath Mountains, and on the east by the Modoc Plateau and Great Basin. The bioregion encompasses the Southern Cascades section of Miles and Goudey...

  8. Serological evidence of rift valley fever virus among acute febrile patients in Southern Mozambique during and after the 2013 heavy rainfall and flooding: implication for the management of febrile illness.

    PubMed

    Gudo, Eduardo Samo; Pinto, Gabriela; Weyer, Jacqueline; le Roux, Chantel; Mandlaze, Arcildo; José, Américo Feriano; Muianga, Argentina; Paweska, Janusz Tadeusz

    2016-06-08

    Rift Valley fever virus (RVFV) remains heavily neglected in humans in Mozambique, even though recent outbreaks were reported in neighboring countries in humans and several cases of RVFV in cattle were reported in several districts in Mozambique. We conducted a cross sectional study during and after severe flooding that occurred in 2013 in Mozambique. Paired acute and convalescent serum samples were tested from febrile patients attending a primary health care unit in a suburban area of Maputo city for the presence of IgG and IgM antibodies against Rift Valley fever virus (RVFV) using enzyme-linked immunosorbent assay (ELISA). Seroconversion of IgG anti-RVFV was observed in 5 % (10/200) of convalescent patients and specific IgM anti-RVFV was detected in one acute patient (0.5 %; 1/200). All sera from acute patient tested negative by real time PCR. In conclusion, our results suggest that RVF represent an important but neglected cause of febrile illness following periods of flooding in southern Mozambique.

  9. Monitoring Seasonal Land Subsidence and Uplift in the Green Valley Area of the Tucson Active Management Area Groundwater Basin, Southern Arizona using Interferometric Synthetic Aperture Radar (InSAR) Data and Global Navigation Satellite System (GNSS) Data

    NASA Astrophysics Data System (ADS)

    Conway, B. D.

    2013-12-01

    The Green Valley land subsidence feature is located in southern Arizona, approximately 20 miles south of the Tucson metropolitan area within the town of Sahuarita. Groundwater levels fluctuate as much as 110 feet annually, caused by seasonal pumping demands of a nearby pecan orchard. Recent Arizona Department of Water Resources (ADWR) InSAR data and GNSS survey data reveal that seasonal land subsidence and subsequent uplift are occurring as a direct result of seasonal groundwater level fluctuations. Data from a nearby ADWR transducer shows that the groundwater level begins to decline around middle to late February, dropping as much as 110 feet by the end of June. Groundwater levels generally remain somewhat stable until the middle of October, when the groundwater level begins to rise. Groundwater levels will rise as much as 110 feet by the middle of February; a complete 12-month recovery. ADWR InSAR and GNSS survey data show that land subsidence occurs from February until May followed by a stable period, then uplift occurs from October to February. The Green Valley land subsidence feature is a dynamic hydrogeological system that requires continued deformation monitoring using both InSAR and GNSS data. Radarsat-2 Interferograms that illustrate both seasonal subsidence and uplift. Surveyed elevation and groundwater level change data that document how seasonal groundwater fluctuations result in seasonal land subsidence and uplift.

  10. Strontium isotopic signatures of the streams and lakes of Taylor Valley, Southern Victoria Land, Antarctica: Chemical weathering in a polar climate

    USGS Publications Warehouse

    Lyons, W.B.; Nezat, C.A.; Benson, L.V.; Bullen, T.D.; Graham, E.Y.; Kidd, J.; Welch, K.A.

    2002-01-01

    We have collected and analyzed a series of water samples from three closed-basin lakes (Lakes Bonney, Fryxell, and Hoare) in Taylor Valley, Antarctica, and the streams that flow into them. In all three lakes, the hypolimnetic waters have different 87Sr/86Sr ratios than the surface waters, with the deep water of Lakes Fryxell and Hoare being less radiogenic than the surface waters. The opposite occurs in Lake Bonney. The Lake Fryxell isotopic ratios are lower than modern-day ocean water and most of the whole-rock ratios of the surrounding geologic materials. A conceivable source of Sr to the system could be either the Cenozoic volcanic rocks that make up a small portion of the till deposited in the valley during the Last Glacial Maximum or from marble derived from the local basement rocks. The more radiogenic ratios from Lake Bonney originate from ancient salt deposits that flow into the lake from Taylor Glacier and the weathering of minerals with more radiogenic Sr isotopic ratios within the tills. The Sr isotopic data from the streams and lakes of Taylor Valley strongly support the notion documented by previous investigators that chemical weathering has been, and is currently, a major process in determining the overall aquatic chemistry of these lakes in this polar desert environment.

  11. Valley Floor

    NASA Technical Reports Server (NTRS)

    2003-01-01

    MGS MOC Release No. MOC2-529, 30 October 2003

    This Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) image shows the floor of an ancient valley located near the Pyrrhae Chaos region of Mars. This valley might have been carved by liquid water, but today no evidence remains that a fluid ever flowed through it. Long after the valley formed, its floor was covered by large, windblown, ripple-like dunes. This picture is located near 13.0oS, 31.2oW. The image is illuminated by sunlight from the upper left and covers an area 3 km (1.9 mi) wide.

  12. Digital hydrographic, land use/land cover, and hydrologic unit boundary files for the Death Valley region of southern Nevada and southeastern California processed from US Geological Survey 1:100,000- and 1:250,000-scale digital data files

    SciTech Connect

    Turner, A.K.; D`Agnese, F.A.; Faunt, C.C.

    1996-04-01

    Digital hydrographic and land-use/land-cover data have been compiled into a digital geographic data base for an {approx}100,000-km{sup 2} area of the Southern Great Basin, the Death Valley region of southern Nevada and SE California, located between lat 35{degree}N, long 115{degree}W and lat 38{degree}N, long 118{degree}W. This region includes the Nevada Test Site at Yucca Mountain and adjacent parts of southern Nevada and eastern California. The data base was compiled from USGS data files distributed by the USGS Earth Scinece Information Center. The data files were converted into six thematic ARC/INFO map coverages representing the Death Valley region.

  13. Valley fever

    MedlinePlus

    ... southwestern United States, and in Central and South America. You get it by breathing in the fungus ... that causes Valley fever) Chest x-ray Sputum culture Sputum smear (KOH test) Tests done for more ...

  14. The organic and mineral matter contents in deposits infilling floodplain basins: Holocene alluviation record from the Kłodnica and Osobłoga river valleys, southern Poland

    NASA Astrophysics Data System (ADS)

    Wójcicki, K. J.; Marynowski, L.

    2012-07-01

    The work examines the timing and environmental conditions of floodplain sedimentation in the valleys of the upland Kłodnica and piedmont Osobłoga rivers in the Upper Odra River basin. A distribution of 52 14C-ages shows relatively high floodplain sedimentation at the Late Glacial-Holocene transition, more stable floodplain environments since the Early (in the Kłodnica Valley) and Middle Holocene (in the Osobłoga Valley) and a gradual increase in floodplain deposition in the Late Holocene (since < 3.4 kyr BP). Organic matter [OM] and mineral matter [MM] fluctuations were correlated with variables responsible for the activation of erosion (i.e. vegetation changes, human impact and hydrological events) as well as factors affecting the local record of sedimentation (i.e. valley morphology, hydrologic conditions and episodes of local erosion). A clear relationship is shown between an increase in alluviation and climate- or human-induced extension of unforested areas. The deposition of mineral-rich sediments increases rapidly during periods characterized by non-arboreal pollen values exceeding approximately 8% in pollen diagrams. On the other hand, the results obtained do not confirm significant interactions between Holocene changes in forest composition and alluviation. Despite the settlement of agrarian groups, the sedimentary record of human activity in the Osobłoga catchment is very poor during the Neolithic and early Bronze Age. A large-scale alluviation of the Osobłoga and Kłodnica valleys was initiated during the settlement of people of the Lusatian culture from the middle Bronze Age and escalated in the early Middle Ages and Modern Times. The deposition of products of soil erosion was limited to between ca. 1.9-1.2 kyr BP, probably due to demographic regression during the Migration Period. Comparison of OM/MM fluctuations with phases of increased fluvial activity does not show a relationship between Holocene wetter phases and catchment sediment yield

  15. A note on the correlation between geophysical observations and seismicity in the Arava/(Araba) Valley at the southern part of the Dead Sea fault

    USGS Publications Warehouse

    Rybakov, M.; Shapira, A.; Al-Zoubi, A.; ten Brink, U.; Hofstetter, R.; Kraeva, N.; Feldman, L.

    2006-01-01

    The spatial distribution of the earthquakes in the Arava Valley, a 150-km section of the Dead Sea Transform, is compared for the first time with the local subsurface geological features derived from geophysical and geological data. Gravity data suggested that the Gharandal, Timna, and Elat basins were filled by low-density young sediments. These features were confirmed by seismic reflection profiles and high-resolution aeromagnetic (HRAM) survey. The HRAM survey delineated the trace of the Dead Sea Transform (DST), which separates magnetic anomalies in the eastern and western parts of the valley, and revealed the occurrence of the unknown deep magmatics. Overall, the earthquake activity appears to be strongly related to the Dead Sea Transform. However, on a local scale, there is no apparent correlation between the seismicity and the mapped fault segments comprising the DST fault system. Absence of the correlation may be a result of insufficient accuracy of the earthquake localization and/or the inclined fault plane. However, in spite of such inaccuracy, it is clearly observed that the large clusters of the low-magnitude earthquakes coincide well with the sedimentary basins. Two pronounced clusters appear to coincide with the subsurface magmatics. We assume that the subsurface geology predetermines areas of stress accumulation and earthquakes. These areas can be the end of faults, or fault jogs, which sometimes create basins. Magmatism can also be affected by the stress field and predetermine the stress and earthquakes' allocation. ?? 2007 Science From Israel/LPPLtd.

  16. Analysing the effects of the 2002 McNally fire on air quality in the San Joaquin Valley and southern Sierra Nevada, California

    Treesearch

    Ricardo Cisneros; Donald Schweizer; Sharon Zhong; Katharine Hammond; Miguel A. Perez; Qinghua Guo; Samuel Traina; Andrzej Bytnerowicz; Deborah H. Bennett

    2012-01-01

    Smoke from wildfires can expose individuals and populations to elevated levels of particulate matter (PM) and ozone (O3). Between 21 July and 26 August 2002, the McNally Fire burned over 150 000 acres (61 000 ha). The fire occurred in the Sequoia National Forest, in the southern Sierra Nevada of California. This study evaluated the effects of the McNally Fire on air...

  17. Luminescence ages for alluvial-fan deposits in Southern Death Valley: Implications for climate-driven sedimentation along a tectonically active mountain front

    USGS Publications Warehouse

    Sohn, M.F.; Mahan, S.A.; Knott, J.R.; Bowman, D.D.

    2007-01-01

    Controversy exists over whether alluvial-fan sedimentation along tectonically active mountain fronts is driven by climatic changes or tectonics. Knowing the age of sedimentation is the key to understanding the relationship between sedimentation and its cause. Alluvial-fan deposits in Death Valley and throughout the arid southwestern United States have long been the subjects of study, but their ages have generally eluded researchers until recently. Most mapping efforts have recognized at least four major relative-age groupings (Q1 (oldest), Q2, Q3, and Q4 (youngest)), using observed changes in surface soils and morphology, relation to the drainage net, and development of desert pavement. Obtaining numerical age determinations for these morphologic stages has proven challenging. We report the first optically stimulated luminescence (OSL) ages for three of these four stages deposited within alluvial-fans along the tectonically active Black Mountains of Death Valley. Deposits showing distinct, remnant bar and swale topography (Q3b) have OSL ages from 7 to 4 ka., whereas those with moderate to poorly developed desert pavement and located farther above the active channel (Q3a) have OSL ages from 17 to 11 ka. Geomorphically older deposits with well-developed desert pavement (Q2d) have OSL ages ???25 ka. Using this OSL-based chronology, we note that alluvial-fan deposition along this tectonically active mountain front corresponds to both wet-to-dry and dry-to-wet climate changes recorded globally and regionally. These findings underscore the influence of climate change on alluvial fan deposition in arid and semi-arid regions. ?? 2007 Elsevier Ltd and INQUA.

  18. Inter-epidemic Acquisition of Rift Valley Fever Virus in Humans in Tanzania

    PubMed Central

    Sumaye, Robert David; Abatih, Emmanuel Nji; Thiry, Etienne; Amuri, Mbaraka; Berkvens, Dirk; Geubbels, Eveline

    2015-01-01

    Background In East Africa, epidemics of Rift Valley fever (RVF) occur in cycles of 5–15 years following unusually high rainfall. RVF transmission during inter-epidemic periods (IEP) generally passes undetected in absence of surveillance in mammalian hosts and vectors. We studied IEP transmission of RVF and evaluated the demographic, behavioural, occupational and spatial determinants of past RVF infection. Methodology Between March and August 2012 we collected blood samples, and administered a risk factor questionnaire among 606 inhabitants of 6 villages in the seasonally inundated Kilombero Valley, Tanzania. ELISA tests were used to detect RVFV IgM and IgG antibodies in serum samples. Risk factors were examined by mixed effects logistic regression. Findings RVF virus IgM antibodies, indicating recent RVFV acquisition, were detected in 16 participants, representing 2.6% overall and in 22.5% of inhibition ELISA positives (n = 71). Four of 16 (25.0%) IgM positives and 11/71 (15.5%) of individuals with inhibition ELISA sero-positivity reported they had had no previous contact with host animals. Sero-positivity on inhibition ELISA was 11.7% (95% CI 9.2–14.5) and risk was elevated with age (odds ratio (OR) 1.03 per year; 95% CI 1.01–1.04), among milkers (OR 2.19; 95% CI 1.23–3.91), and individuals eating raw meat (OR 4.17; 95% CI 1.18–14.66). Households keeping livestock had a higher probability of having members with evidence of past infection (OR = 3.04, 95% CI = 1.42–6.48) than those that do not keep livestock. Conclusion There is inter-epidemic acquisition of RVFV in Kilombero Valley inhabitants. In the wake of declining malaria incidence, these findings underscore the need for clinicians to consider RVF in the differential diagnosis for febrile illnesses. Several types of direct contact with livestock are important risk factors for past infection with RVFV in this study’s population. However, at least part of RVFV transmission appears to have occurred

  19. Data from exploratory sampling of groundwater in selected oil and gas areas of coastal Los Angeles County and Kern and Kings Counties in southern San Joaquin Valley, 2014–15: California oil, gas, and groundwater project

    USGS Publications Warehouse

    Dillon, David B.; Davis, Tracy A.; Landon, Matthew K.; Land, Michael T.; Wright, Michael T.; Kulongoski, Justin T.

    2016-12-09

    Exploratory sampling of groundwater in coastal Los Angeles County and Kern and Kings Counties of the southern San Joaquin Valley was done by the U.S. Geological Survey from September 2014 through January 2015 as part of the California State Water Resources Control Board’s Water Quality in Areas of Oil and Gas Production Regional Groundwater Monitoring Program. The Regional Groundwater Monitoring Program was established in response to the California Senate Bill 4 of 2013 mandating that the California State Water Resources Control Board design and implement a groundwater-monitoring program to assess potential effects of well-stimulation treatments on groundwater resources in California. The U.S. Geological Survey is in cooperation with the California State Water Resources Control Board to collaboratively implement the Regional Groundwater Monitoring Program through the California Oil, Gas, and Groundwater Project.Many researchers have documented the utility of different suites of chemical tracers for evaluating the effects of oil and gas development on groundwater quality. The purpose of this exploratory sampling effort was to determine whether tracers reported in the literature could be used effectively in California. This reconnaissance effort was not designed to assess the effects of oil and gas on groundwater quality in the sampled areas. A suite of water-quality indicators and geochemical tracers were sampled at groundwater sites in selected areas that have extensive oil and gas development. Groundwater samples were collected from a total of 51 wells, including 37 monitoring wells at 17 multiple-well monitoring sites in coastal Los Angeles County and 5 monitoring wells and 9 water-production wells in southern San Joaquin Valley, primarily in Kern and Kings Counties.Groundwater samples were analyzed for field water-quality indicators; organic constituents, including volatile and semi-volatile organic compounds and dissolved organic carbon indicators; naturally

  20. Southern Nevadas Club Ride Commuter Service Wins EPA Honor

    EPA Pesticide Factsheets

    · Clean Air Partners Program - CLEAN AIR Force of Central Texas · Club Ride Commuter Services - Regional Transportation Commission of Southern Nevada · Air Quality Partnership of the Delaware Valley - Delaware Valley Regional Planning

  1. Constraints on Shallow Crustal Structure across the San Andreas Fault Zone, Coachella Valley, Southern California: Results from the Salton Seismic Imaging Project (SSIP)

    NASA Astrophysics Data System (ADS)

    Hernandez, A.; Persaud, P.; Bauer, K.; Stock, J. M.; Fuis, G. S.; Hole, J. A.; Goldman, M.

    2015-12-01

    The strong influence of basin structure and crustal heterogeneities on seismic wave propagation suggests that these factors should be included in calculations of strong ground shaking. Knowledge of the shallow subsurface is thus essential for an accurate seismic hazard estimate for the densely populated Coachella Valley, the region north of the potential M7.8 rupture near the Salton Sea. Using SSIP data, we analyzed first arrivals from nine 65-911 kg explosive shots recorded along a profile in the Coachella Valley in order to evaluate the interpretation of our 2D tomographic results and give added details on the structural complexity of the shallow crust. The line extends 37 km from the Peninsular Ranges to the Little San Bernardino Mountains crossing the major strands of the San Andreas Fault Zone. We fit traveltime curves to our picks with forward modeling ray tracing, and determined 1D P-wave velocity models for traveltime arrivals east and west of each shot, and a 2D model for the line. We also inferred the geometry of near-vertical faults from the pre-stack line migration method of Bauer et al. (2013). In general, the 1D models east of individual shots have deeper basement contacts and lower apparent velocities, ~5 km/s at 4 km depth, whereas the models west of individual shots have shallower basement and velocities up to 6 km/s at 2 km depth. Mismatches in basement depths (assuming 5-6 km/s) between individual 1D models indicate a shallowly dipping basement, deepening eastward towards the Banning Fault and shoaling abruptly farther east. An east-dipping structure in the 2D model also gives a better fit than horizontal layers. Based on high velocity zones derived from traveltimes at 9-20 km from the western end of the line, we included an offset from ~2 km to 4 km depth near the middle of the line, which significantly improved the 2D model fit. If fault-related, this offset could represent the Garnet Hill Fault if it continues southward in the subsurface.

  2. Seroprevalence of Leptospira borgpetersenii serovar javanica infection among dairy cattle, rats and humans in the Cauvery river valley of southern India.

    PubMed

    Natarajaseenivasan, Kalimuthusamy; Vedhagiri, Kumaresan; Sivabalan, Vadivel; Prabagaran, Shanmugarajan G; Sukumar, Sethurajan; Artiushin, Sergey C; Timoney, John F

    2011-05-01

    Leptospirosis is a major problem of dairy farms in Tamilnadu, India, resulting in abortions, stillbirths and infertility. Serologic and genetic analyses of samples from cattle, humans and rodents were performed in order to estimate infection prevalence and identify leptospiral species. Five hundred and fifteen sera and 76 urine samples were collected from dairy cattle on 25 farms including a farm that practiced rat control. Sera and kidney samples were also collected from field rats (Rattus norvegicus) in the vicinity of these farms. In addition, sera were collected from farm workers. Serum antibody was measured by the microscopic agglutination test. Leptospires isolated from blood, kidney, and urine were characterized as to serovar. Genomospecies were predicted using random amplified polymorphic DNA (RAPD) profiling. SecY gene sequencing was performed as a tool for tracing of source. Seroprevalence of 87.%, 51.% and 76.5% for cattle, rats and humans, respectively, was observed on endemic farms. Prevalences on a non-endemic farm were lower. Antibodies to Autumnalis, Javanica, Icterohaemorrhagiae and Pomona predominated in both cattle and rats. Thirteen isolates from rat kidneys were identified as serogroup Javanica, serovar Javanica. RAPD comparisons and secY gene sequencing identified these isolates as Leptospira borgpetersenii. These results altogether indicated that L. borgpetersenii was the dominant species in these areas with serovar Javanica apparently derived from rats which provided an important source of infection in cattle resulting a high incidence of infertility, abortion and.still-birth in the Cauvery river valley, Tiruchirappalli, Tamilnadu.

  3. Is it working? A look at the changing nutrient practices in the Southern Willamette Valley’s Groundwater Management Area

    EPA Science Inventory

    Groundwater nitrate contamination affects thousands of households in the southern Willamette Valley and many more across the Pacific Northwest. The southern Willamette Valley Groundwater Management Area (SWV GWMA) was established in 2004 to address the occurrence of high groundw...

  4. Is it working? A look at the changing nutrient practices in the Southern Willamette Valley’s Groundwater Management Area

    EPA Science Inventory

    Groundwater nitrate contamination affects thousands of households in the southern Willamette Valley and many more across the Pacific Northwest. The southern Willamette Valley Groundwater Management Area (SWV GWMA) was established in 2004 to address the occurrence of high groundw...

  5. Lithologic properties of carbonate-rock aquifers at five test wells in the Coyote Spring Valley Area, southern Nevada, as determined from geophysical logs. Water resources investigation report

    SciTech Connect

    Berger, D.L.

    1992-01-01

    Regional ground-water flow systems in the carbonate-rock aquifers in southern Nevada were evaluated as potential sources for water supply as part of the Nevada Carbonate Aquifers Program. Geophysical log analyses indicated that the test wells penetrate carbonate rocks, which vary in composition from limestone to dolomite and include mixtures of both. Calcite was found to be the predominant matrix mineral and shales made up of only a small percentage of the overall rock. Bulk-density measurements averaged 2.65 grams per cubic centimeter and the matrix density estimates averaged 2.76 grams per cubic centimeter. Increased amounts of silica in the matrix mineralogy were associated with greater total porosity values. The log analyses indicated an average of 4.7 percent porosity for 43 zones in the test wells.

  6. Physical and institutional vulnerability assessment method applied in Alpine communities. Preliminary Results of the SAMCO-ANR Project in the Guil Valley (French Southern Alps)

    NASA Astrophysics Data System (ADS)

    Carlier, Benoit; Dujarric, Constance; Puissant, Anne; Lissak, Candide; Viel, Vincent; Bétard, François; Madelin, Malika; Fort, Monique; Arnaud-Fassetta, Gilles

    2015-04-01

    The Guil catchment is particularly prone to torrential and gravitational hazards such as floods, debris flows, landslides or avalanches due to several predisposing factors (bedrock supplying abundant debris, strong hillslope-channel connectivity) in a context of summer Mediterranean rainstorms as triggers. These hazards severely impact the local population (fatalities, destruction of buildings and infrastructures, loss of agricultural land, road closures). Since the second half of the 20th century, the progressive decline of agro-pastoralism and the development of tourism activities led to a concentration of human stakes on alluvial cones and valley bottom, therefore an increase of vulnerability for mountainous communities. Following the 1957 and 2000 catastrophic floods and the 1948 and 2008 avalanche episodes, some measures were taken to reduce exposure to risks (engineering works, standards of construction, rescue training…). Nevertheless, in front of urban expansion (land pressures and political pressures) and obsolescence of the existing protective measures, it is essential to reassess the vulnerability of the stakes exposed to hazards. Vulnerability analysis is, together with hazard evaluation, one of the major steps of risk assessment. In the frame of the SAMCO project designed for mountain risk assessment, our goal is to estimate specific form of vulnerability for communities living in the Upper Guil catchment in order to provide useful documentation for a better management of the valley bottom and the implementation of adequate mitigation measures. Here we present preliminary results on three municipalities of the upper Guil catchment: Aiguilles, Abriès, and Ristolas. We propose an empirical semi-quantitative indicator of potential hazards consequences on element at risk (based on GIS) with an application to different (local and regional scale) scales. This indicator, called Potential Damage Index, enable us to describe, quantify, and visualize direct

  7. A 200,000-year record of late Quaternary Aeolian sedimentation on the Southern High Plains and nearby Pecos River Valley, USA

    NASA Astrophysics Data System (ADS)

    Rich, J.; Stokes, S.

    2011-03-01

    Presently stabilized Southern High Plains (SHP) dune systems have been repeatedly re-activated during the past 200,000 years, providing an archive of environmental and related climatic change for the late Quaternary. Our data set of 38 optically dated samples from four different localities identifies eolian activity from late-middle Pleistocene to the historic period. Oldest eolian sediments are from the Blackwater Draw Formation and indicate accretion during late-middle to late Pleistocene. Younger sediments dating from the later Pleistocene through the Holocene are found in the Muleshoe, Lea-Yoakum, Mescalero, and Monahans dunes that overlie the Blackwater Draw Formation. Muleshoe dunes accreted during the Late Pleistocene between 31 ± 3 and 27 ± 2 ka, while Holocene deposition transpired 7.5 ± 0.4, 4.0 ± 0.7 ka through 3.6 ± 0.4 ka, and between 1.3 ± 0.2 and 1.1 ± 0.1 ka. A period of dune building for Lea-Yoakum dune sediments occurred during the late Pleistocene (48 ± 5 ka), and the later Holocene (3.6 ± 0.4 ka). Mescalero and Monahans dunes were accreting during the later Pleistocene between 29 ± 3 and 22 ± 2 ka followed by a sequence of eolian sand deposited ca. 15 ka. Holocene eolian sedimentation for the Mescalero and Monahans dunes occurred 7.5 ± 0.8, 5.1 ± 0.5, 4.3 ± 0.4, and 2.0 ± 0.3 ka. Historic eolian deposition is identifiable in the dune chronology with multiple optical age estimates overlapping established drought events recorded ca. 1890, 1910, 1920, and during the 1930's when the North American "Dust Bowl" transpired. These Quaternary eolian deposits mantling the Southern High Plains are an important component of the surficial material of the region and provide a rich archive of past climatic change.

  8. Impact of tsetse and trypanosomiasis control on cattle herd composition and calf growth and mortality at Arbaminch District (Southern Rift Valley, Ethiopia).

    PubMed

    Gechere, Geja; Terefe, Getachew; Belihu, Kelay

    2012-10-01

    The effect of tsetse/trypanosomiasis control on cattle herd composition and growth and mortality of calves in tsetse controlled (by Southern Tsetse Eradication Project (STEP)) and uncontrolled blocks in southern Ethiopia was assessed. Structured questionnaire was used to interview 182 households to estimate cattle herd composition and calf mortality. Calves were bled to examine the presence of trypanosomes by the buffy coat technique. Forty NGU traps were deployed and fly catches determined. A case-control study was performed on 40 calves for 6 months to estimate calve growth parameters. Accordingly, the mean cattle herd size was lower in tsetse-controlled block than in the uncontrolled block, whereas the relative number of calves in a herd tend to be higher in the tsetse-controlled block (P = 0.06). While there was no report of cattle mortality in tsetse-controlled block, 16.48 % of the respondents have lost calves in tsetse-uncontrolled block in 1 year time. The prevalence of trypanosome positive calves was 2.95 % for uncontrolled block but no positive case in tsetse-controlled block. The apparent densities of flies/trap/day in tsetse-uncontrolled block were 30-fold higher than in tsetse-controlled block (P < 0.01). The case-control study revealed that the mean body weight gain of calves in tsetse-controlled block (40.23 ± 0.7 kg) was significantly higher than that of the uncontrolled block (34.74 ± 0.68 kg). The above findings strongly suggest that the intervention by the STEP project has significantly reduced tsetse population and trypanosomiasis consequently contributing to improved calf growth and survival.

  9. Reconstructing the Late Cretaceous inversion of the Roer Valley Graben (southern Netherlands) using a new model that integrates burial and provenance history with fission track thermochronology

    NASA Astrophysics Data System (ADS)

    Luijendijk, E.; van Balen, R. T.; Ter Voorde, M.; Andriessen, P. A. M.

    2011-06-01

    Apatite fission track thermochronology is a powerful tool for the reconstruction of the thermal and geological evolution of sedimentary basins. However, reconstructing basin evolution using thermochronological data is complicated by the fact that sediments also record the thermal history of their source areas. Moreover, samples frequently contain grains from multiple source areas. We have constructed a new numerical model that integrates sediment burial and thermal history with provenance history scenarios and that uses the derived thermal history to calculate synthetic apatite fission track data. We have applied this model to study the evolution of the Roer Valley Graben and to explore the dependency of fission track data on provenance and basin thermal history. Samples that are buried at shallow depths (<1400 m) preserve a mix of late Paleozoic and early Mesozoic provenance ages that correspond to the Caledonian and Variscan orogenic events of the sediment source areas, the London-Brabant and Ardenno-Rhenish massifs, respectively, with varying degrees of subsequent exhumation. Using this knowledge about the inherited thermal history, fission track data of Mesozoic sediments could be used to constrain the Late Cretaceous inversion of the basin with an accuracy of ±250 to ±500 m. These results show that inversion-related exhumation was localized, reaching a maximum of 750 to 1250 m in the eastern part of the basin, while not exceeding 500 m in the western half of the basin. These results are in agreement with the distribution of preserved preinversion sediments and syninversion sediment accumulations that flank the northeastern part of the basin.

  10. River-spring connectivity and hydrogeochemical interactions in a shallow fractured rock formation. The case study of Fuensanta river valley (Southern Spain)

    NASA Astrophysics Data System (ADS)

    Barberá, J. A.; Andreo, B.

    2017-04-01

    In upland catchments, the hydrology and hydrochemistry of streams are largely influenced by groundwater inflows, at both regional and local scale. However, reverse conditions (groundwater dynamics conditioned by surface water interferences), although less described, may also occur. In this research, the local river-spring connectivity and induced hydrogeochemical interactions in intensely folded, fractured and layered Cretaceous marls and marly-limestones (Fuensanta river valley, S Spain) are discussed based on field observations, tracer tests and hydrodynamic and hydrochemical data. The differential flow measurements and tracing experiments performed in the Fuensanta river permitted us to quantify the surface water losses and to verify its direct hydraulic connection with the Fuensanta spring. The numerical simulations of tracer breakthrough curves suggest the existence of a groundwater flow system through well-connected master and tributary fractures, with fast and multi-source flow components. Furthermore, the multivariate statistical analysis conducted using chemical data from the sampled waters, the geochemical study of water-rock interactions and the proposed water mixing approach allowed the spatial characterization of the chemistry of the springs and river/stream waters draining low permeable Cretaceous formations. Results corroborated that the mixing of surface waters, as well as calcite dissolution and CO2 dissolution/exsolution, are the main geochemical processes constraining Fuensanta spring hydrochemistry. The estimated contribution of the tributary surface waters to the spring flow during the research period was approximately 26-53% (Fuensanta river) and 47-74% (Convento stream), being predominant the first component during high flow and the second one during the dry season. The identification of secondary geochemical processes (dolomite and gypsum dissolution and dedolomitization) in Fuensanta spring waters evidences the induced hydrogeochemical

  11. Martian oceans, valleys and climate

    USGS Publications Warehouse

    Carr, M.H.

    2000-01-01

    The new Mars Global Surveyor altimetry shows that the heavily cratered southern hemisphere of Mars is 5 km higher that the sparely cratered plains of the northern hemisphere. Previous suggestions that oceans formerly occupied that northern plains as evidenced by shorelines are partly supported by the new data. A previously identified outer boundary has a wide range of elevations and is unlikely to be a shoreline but an inner contact with a narrow range of elevations is a more likely candidate. No shorelines are visible in the newly acquired, 2.5 metre/pixel imaging. Newly imaged valleys provide strong support for sustained or episodic flow of water across the Martian surface. A major surprise, however, is the near absence of valleys less than 100 m across. Martian valleys seemingly do not divide into ever smaller valleys as terrestrial valleys commonly do. This could be due to lack of precipitation or lack of surface runoff because of high infiltration rates. High erosion rates and supports warm climates and presence of large bodies of water during heavy bombardment. The climate history and fate of the water after heavy bombardment remain cotroversial.

  12. Hypothesis on the origin of lineaments in the LANDSAT and SLAR images of precambrian soil in the low Contas River Valley (southern Bahia)

    NASA Technical Reports Server (NTRS)

    Liu, C. C. (Principal Investigator); Rodrigues, J. E.

    1984-01-01

    Examination of LANDSAT and SLAR images in southern Bahia reveals numerous linear features, which are grouped in five sets, based on their trends: N65 degrees E, N70 degrees W, N45 degrees E and NS/N15 degrees E. Owing to their topographic expressions, distributive patterns, spacing between individual lineaments and their mutual relationships, the lineament sets of N65 degrees E and N70 degrees W, as well as the sets of N40 degrees E and N45 degrees W, are considered as two groups of conjugate shear fractures and the former is older and is always cut by the latter. Their conjugate shear angles are 45 degrees and 85 degrees and their bisector lines are approximately in east-west and north-south directions, respectively. According to Badgeley's argumentation on the conjugate shear angles, the former conjugate shear fractures would be caused by: (1) vertical movements, and the bisector of their conjugate angle would be parallel to the long axis of horsting or folding, or (2) by a compressive force in the east-west direction and under a condition of low confining pressure and temperature.

  13. Site response variation due to the existence of near-field cracks based on strong motion records in the Shi-Wen river valley, southern Taiwan

    NASA Astrophysics Data System (ADS)

    Wu, Chi-Shin; Yu, Teng-To; Peng, Wen-Fei; Yeh, Yeoin-Tein; Lin, Sih-Siao

    2014-10-01

    Site effect analysis has been applied to investigate soil classification, alluvium depth, and fracture detection, although the majority of previous studies have typically focused only on the response of large-scale single structures. In contrast, we investigated the site effect for small-scale cracks using a case study in southern Taiwan to provide a means of monitoring slope stability or foundation integrity in situ using only an accelerometer. We adopted both the reference site and horizontal-to-vertical spectral ratio methods. We obtained seismographs associated with the typhoon-related development of a crack set (52 m long, 5 m deep) in a steep slope and compared the resonance frequency between two conditions (with and without cracks). Moreover, we divided the seismic waves into P, S, and coda waves and examined the seismic source effect. Our results demonstrate that frequencies of 14.5-17.5 Hz are most sensitive to these cracks, particularly for the E-W component of the P-waves, which coincides with the crack’s strike. Peak ground acceleration, which is controlled by seismic moment and attenuated distance, is another important factor determining the resonance results. Our results demonstrate that the ratio of temporal seismic waves can be used to detect the existence of nearby subsurface cracks.

  14. Further Resolution of Past Earthquake Surface Ruptures at the Carrizo Wash Site, Superstition Mountain Strand of the San Jacinto Fault, Imperial Valley, Southern California.

    NASA Astrophysics Data System (ADS)

    Verdugo, D.; Ragona, D. E.; Rockwell, T. K.

    2005-12-01

    We present results from new trench exposures in Carrizo Wash along the northernmost part of the Superstition Mountain strand (SMF) of the San Jacinto Fault, southern California. Prior paleoseismic work by Ragona (2003) recovered evidence for 7 earthquake events, 3 of which occurred in the past 1000 years. The most recent event produced only 15 cm of slip and is only recognized along the Coyote Creek Fault (CCF). The other two recognized events cumulatively produced nearly 6 m of slip. However, an erosional unconformity in the initial excavations removed evidence for at least one event, based on problematic correlations to nearby sites resulting from mismatches in both the number of recognized lake units as well as the relative stratigraphic position of events with respect to the lakes. The new trenches, south of the effects of the erosional channel, contain evidence for an additional event and an additional delta-lake sequence not present in the original exposures. The new event likely correlates to the penultimate event at the Northern Shoreline site (Gurrola and Rockwell, 1996). Thus, the observed 6 m of slip was mostly accommodated by three events, suggesting about 2 m of slip per event for large SMF ruptures. Our new observations also agree well with data from four other nearby trench sites along the CCF and SMF, and suggest that 1) the SMF has ruptured in only three large events in the past 1100 years, 2) at least two of these events are likely recognized along the CCF, indicating that the step-over between SMF and CCF is soft in large events, 3) most CCF ruptures do not propagate onto the SMF, indicating that the step-over is hard for small displacements, such as 1968-type events (30-50 cm of slip). These observations support the concept of segmentation but indicate that a perceived segment boundary may be transparent if slip exceeds a threshold value.

  15. The use of heavy metal concentrations and dendrochronology in the reconstruction of sediment accumulation, Mała Panew River Valley, southern Poland

    NASA Astrophysics Data System (ADS)

    Ciszewski, Dariusz; Malik, Ireneusz

    2004-03-01

    Heavy metal concentrations were investigated in overbank sediments of the Mala Panew River, southern Poland. Samples were collected from seven vertical profiles located within channel infills of a 20th century floodplain at three sites, each up to 50 m wide. In each profile, 15-24 samples were collected and analysed for Ba, Cd, Cu, Pb, and Zn. Sequential extraction of these elements was carried out in the 0.063-mm fraction of selected samples. Additionally, the age of the oldest trees growing close to the profiles has been used to estimate the initiation of sediment accumulation there. Ba, Cu, and Pb, which occur mostly in less mobile, moderately reducible, and residual fractions, were used for sediment dating. Zn and Cd, which in 50-75% occur in the mobile exchangeable fraction, were not suitable for dating. Correlation of Ba, Cu, and Pb concentrations in vertical profiles with changes in the load of effluents discharged to the river showed abrupt changes in the thickness of the strongly polluted sediments across the floodplains. A comparison of the relative changes between heavy metal peaks in sediments of similar age in the different profiles suggests a variable rate of downward metal migration. In general, none of the heavy metals investigated seems to have been mobilised within the stratigraphic layers above the water table. In layers located at stratigraphically lower levels, the Zn and Cd peaks seem to migrate several centimetres to several decimetres down in the profile. In profiles inundated for several weeks every year, Zn and Cd, as well as the relatively less mobile Ba, Cu, and Pb, have migrated downward by several decimetres. The investigation shows that frequent fluctuations of the water table have blurred the original depositional metal patterns of metal concentrations within a period of less than 40 years.

  16. Southern Appalachian Case Study

    Treesearch

    Charles C. van Sickle

    1999-01-01

    The Southern Appalachian study covers a region of 37.4 million acres. Its mountains, foothills, and valleys stretch from northern Virginia and northern West Virginia to northern Georgia and Alabama. When Native Americans came to the region, forests dominated the landscape and they still do, covering 70% of the land (Figure 32.1). Terrain characteristics are...

  17. TDRS satellite over African Rift Valley, Kenya, Africa

    NASA Technical Reports Server (NTRS)

    1983-01-01

    This post deploy view of a TDRS satellite shows a segment of the African Rift Valley near Lake Baringo, Kenya, Africa (3.0S, 36.0E). The African Rift Valley system is a geologic fault having its origins in southern Turkey, through the near east forming the bed of the Jordan River, Gulf of Aqaba, the Red Sea and down through east Africa. The line of lakes and valleys of east Africa are the result of the faulting activity.

  18. Physical, social and institutional vulnerability assessment in small Alpine communities. Results of the SAMCO-ANR project in the Upper Guil Valley (French Southern Alps)

    NASA Astrophysics Data System (ADS)

    Carlier, Benoit; Dujarric, Constance; Frison-Bruno, Nikita; Puissant, Anne; Lissak, Candide; Madelin, Malika; Viel, Vincent; Bétard, François; Fort, Monique; Arnaud-Fassetta, Gilles

    2016-04-01

    The Upper Guil catchment is particularly prone to hydromorphological hazards such as torrential floods, debris flows, landslides or avalanches. Following the catastrophic events of the last 60 years (1957, 1978, 2000, and 2008), some measures were taken to reduce exposure to risks (engineering works, standards of construction, rescue training…). Nevertheless, the development of urban settlement in endangered areas and the obsolescence of the existing protective measures revealed the necessity to reassess the vulnerability of the different stakes exposed to hazards and to take into account of these various component parts of the vulnerability (not only physical but also social, etc.). In addition, catastrophic events should be more frequent in the French Southern Alps, according to the last GIEC report. In the frame of the SAMCO project designed for mountain risk assessment in a context of global change, we developed a systemic approach to assess three specific components of vulnerability - physical, social and institutional - for the six municipalities of the Upper Guil catchment (Ristolas, Abriès, Aiguilles, Château-Ville-Vieille, Molines-en-Queyras and St-Véran). Physical vulnerability, which represents total potential consequences of hazards on stakes, was estimated and mapped using a GIS model based on an empirical semi-quantitative indicator, the Potential Damage Index (PDI). This index allowed us to quantify and describe both direct (physical injury, structural and functional damage on buildings, network and land cover) and indirect consequences (socio-economic impacts) induced by hazards, by combining weighted parameters (age, state, material, function, etc.) reflecting the exposure of elements at risk. At least 1890 buildings, 367 km² of land cover and 902 km of linear infrastructure were considered. To assess social and institutional vulnerability our approach was based on questionnaires (5% of the total population investigated), interviews and

  19. Rift Valley Fever Outbreak in Livestock, Mozambique, 2014.

    PubMed

    Fafetine, José M; Coetzee, Peter; Mubemba, Benjamin; Nhambirre, Ofélia; Neves, Luis; Coetzer, J A W; Venter, Estelle H

    2016-12-01

    In early 2014, abortions and death of ruminants were reported on farms in Maputo and Gaza Provinces, Mozambique. Serologic analysis and quantitative and conventional reverse transcription PCR confirmed the presence of Rift Valley fever virus. The viruses belonged to lineage C, which is prevalent among Rift Valley fever viruses in southern Africa.

  20. Rift Valley Fever Outbreak in Livestock, Mozambique, 2014

    PubMed Central

    Coetzee, Peter; Mubemba, Benjamin; Nhambirre, Ofélia; Neves, Luis; Coetzer, J.A.W.; Venter, Estelle H.

    2016-01-01

    In early 2014, abortions and death of ruminants were reported on farms in Maputo and Gaza Provinces, Mozambique. Serologic analysis and quantitative and conventional reverse transcription PCR confirmed the presence of Rift Valley fever virus. The viruses belonged to lineage C, which is prevalent among Rift Valley fever viruses in southern Africa. PMID:27869589

  1. The hydrology of San Bernardino Valley, California

    USGS Publications Warehouse

    Mendenhall, Walter C.

    1905-01-01

    The San Bernardino basin lies near the eastern end of the valley of southern California.  Under the latter term is included that general lowland area which is definitely limited on the north by the San Gabriel and San Bernardino ranges and on the east by the latter range and the San Jacinto group, but whose southern boundary is irregular and difficult to define.  In this direction there is an interdigitation of ridges and valleys as the Sierra Madre Range of San Diego County dies out toward the north.  The more or less indefinite heights that represent its extension in this direction are separated by lowlands, which in turn are to be regarded as southwest lobes of the well-defined east-west valley that lies along the base of the San Gabriel Range.

  2. Ohio Valley Community Health Information Network.

    ERIC Educational Resources Information Center

    Guard, Roger; And Others

    The Ohio Valley Community Health Information Network (OVCHIN) works to determine the efficacy of delivering health information to residents of rural southern Ohio and the urban and suburban Cincinnati area. OVCHIN is a community-based, consumer-defined demonstration grant program funded by the National Telecommunications and Information…

  3. Cosmogenic Nuclides 10Be-21Ne Burial Dating of Middle Miocene Sedimentary Formation of the Hongliu Valley in Southern Ningxia Basin: A Case of Isotopic Geochronology Study for the Cenozoic Sedimentary Strata

    NASA Astrophysics Data System (ADS)

    Ma, Yan; Zhang, Huiping; Wang, Weitao; Pang, Jianzhang; Zheng, Dewen

    2016-04-01

    Chronology studies for the Cenozoic sedimentary strata based on the magnetostratigraphy cannot afford the unique chronological sequences in the absence of absolute ages from biostratigraphy or volcanic ash chronology. In situ-produced cosmogenic nuclides provide a powerful tool for the sediment dating based on the time-dependent concentration ratio of two nuclides, which are produced in the same mineral but with different half-lives. Thereinto,10Be-26Al is the most widely used nuclide pairs, of which the available dating range spans the Plio-Pleistocene. But the coupling of 10Be with the stable nuclide 21Ne would significantly improve the burial dating range up to the middle Miocene, which is promising in revolutionizing the chronology study for the Late Cenozoic terrestrial sedimentary sequences. We have applied 10Be-21Ne pair for dating the middle Miocene sediments of the Hongliu Valley in southern Ningxia basin. Two major features of the sediments are involved in our study: (1) sediments originated from the steady erosion of the source area, and (2) the burial depth of our sample after deposition is time dependent due to the gradual accumulation of sediments into basin. The post-burial nuclide production is estimated to be less than 3%, including the contribution by muon interactions, of the total nuclide concentrations measured in our sample. Our 10Be-21Ne analysis demonstrates the age of the burial sample is 12.4(+0.6/-0.4) Ma, and the erosion rate at the source area is 0.26±0.01 cm ka-1. The sample's burial age is consistent with the age constraint set by the Hongliugou Formation (16.7-5.4 Ma) which we collected the sample in. Vertebrate fossils of Platybelodon tongxinensis with an age between 12 and 15 Ma exhumated along with our sample further verifies the reliability of our dating results for the middle Miocene sediments.This study has shown the improved age range of cosmogenic-nuclide burial dating method by incorporating the stable nuclide 21Ne, and has

  4. Saline Valley

    NASA Image and Video Library

    2001-10-22

    These images of the Saline Valley area, California, were acquired March 30, 2000 and cover a full ASTER scene (60 by 60 km). Each image displays data from a different spectral region, and illustrates the complementary nature of surface compositional information available as a function of wavelength. This image displays visible and near infrared bands 3, 2, and 1 in red, green, and blue (RGB). Vegetation appears red, snow and dry salt lakes are white, and exposed rocks are brown, gray, yellow and blue. Rock colors mainly reflect the presence of iron minerals, and variations in albedo. Figure 1 displays short wavelength infrared bands 4, 6, and 8 as RGB. In this wavelength region, clay, carbonate, and sulfate minerals have diagnostic absorption features, resulting in distinct colors on the image. For example, limestones are yellow-green, and purple areas are kaolinite-rich. Figure 2 displays thermal infrared bands 13, 12 and 10 as RGB. In this wavelength region, variations in quartz content appear as more or less red; carbonate rocks are green, and mafic volcanic rocks are purple. The image is located at 36.8 degrees north latitude and 117.7 degrees west longitude. http://photojournal.jpl.nasa.gov/catalog/PIA11164

  5. Saline Valley

    NASA Technical Reports Server (NTRS)

    2001-01-01

    [figure removed for brevity, see original site] [figure removed for brevity, see original site] Figure 1 Figure 2

    These images of the Saline Valley area, California, were acquired March 30, 2000 and cover a full ASTER scene (60 by 60 km). Each image displays data from a different spectral region, and illustrates the complementary nature of surface compositional information available as a function of wavelength. This image displays visible and near infrared bands 3, 2, and 1 in red, green, and blue (RGB). Vegetation appears red, snow and dry salt lakes are white, and exposed rocks are brown, gray, yellow and blue. Rock colors mainly reflect the presence of iron minerals, and variations in albedo. Figure 1 displays short wavelength infrared bands 4, 6, and 8 as RGB. In this wavelength region, clay, carbonate, and sulfate minerals have diagnostic absorption features, resulting in distinct colors on the image. For example, limestones are yellow-green, and purple areas are kaolinite-rich. Figure 2 displays thermal infrared bands 13, 12 and 10 as RGB. In this wavelength region, variations in quartz content appear as more or less red; carbonate rocks are green, and mafic volcanic rocks are purple. The image is located at 36.8 degrees north latitude and 117.7 degrees west longitude.

    The U.S. science team is located at NASA's Jet Propulsion Laboratory, Pasadena, Calif. The Terra mission is part of NASA's Science Mission Directorate.

  6. The Valley Networks on Mars

    NASA Astrophysics Data System (ADS)

    Gulick, V. C.

    2002-12-01

    Despite three decades of exploration, the valley networks on Mars still seem to raise more questions than they answer. Valley systems have formed in the southern highlands, along some regions of the dichotomy boundary and the south rim of Valles Marineris, around the rim of some impact craters, and on the flanks of some volcanoes. They are found on some of the oldest and youngest terrains as well as on intermediate aged surfaces. There is surprisingly little consensus as to the formation and the paleoclimatic implications of the valley networks. Did the valleys require a persistent solar-driven atmospheric hydrological cycle involving precipitation, surface runoff, infiltration and groundwater outflow as they typically do on Earth? Or are they the result of magmatic or impact-driven thermal cycling of ground water involving persistent outflow and subsequent runoff? Are they the result of some other process(es)? Ground-water sapping, surface-water runoff, debris flows, wind erosion, and formation mechanisms involving other fluids have been proposed. Until such basic questions as these are definitively answered, their significance for understanding paleoclimatic change on Mars remains cloudy. I will review what is known about valley networks using data from both past and current missions. I will discuss what we have learned about their morphology, environments in which they formed, their spatial and temporal associations, possible formation mechanisms, relation to outflow channel and gully formation, as well as the possible implications for past climate change on Mars. Finally I will discuss how future, meter to submeter scale imaging and other remote sensing observations may shed new light on the debate over the origin of these enigmatic features.

  7. Valley precession and valley polarization in graphene with inter-valley coupling

    NASA Astrophysics Data System (ADS)

    Wu, Qing-Ping; Liu, Zheng-Fang; Chen, Ai-Xi; Xiao, Xian-Bo; Zhang, Heng; Miao, Guo-Xing

    2017-10-01

    We theoretically investigate the valley precession and valley polarization in graphene under inter-valley coupling. Our results show that the inter-valley coupling can induce valley polarization in graphene and also precess valleys in real space in a manner similar to the Rashba spin-orbit interaction rotating spins. Moreover, using strain modulation, we can achieve high valley polarization with large valley-polarized currents. These findings provide a new way to create and manipulate valley polarization in graphene.

  8. Sacramento Valley, CA, USA

    NASA Technical Reports Server (NTRS)

    1973-01-01

    The Sacramento Valley (40.5N, 121.5W) of California is the northern extension of the Central Valley, main agriculture region of the state. Hundreds of truck farms, vineyards and orchards can be seen throughout the length and breadth of the valley which was reclaimed from the desert by means of intensive and extensive irrigation projects.

  9. The Central Valley Hydrologic Model

    NASA Astrophysics Data System (ADS)

    Faunt, C.; Belitz, K.; Hanson, R. T.

    2009-12-01

    and temporal variability in climate, land-use changes, and available surface-water deliveries. For example, the droughts of 1976-77 and 1987-92 led to reduced streamflow and surface-water deliveries and increased evapotranspiration and groundwater pumpage throughout most of the valley, resulting in a decrease in groundwater storage. Since the mid-1990s, annual surface-water deliveries generally have exceeded groundwater pumpage, resulting in an increase or no change in groundwater storage throughout most of the valley. However, groundwater is still being removed from storage during most years in the southern part of the Central Valley. The CVHM is designed to be coupled with Global Climate Models to forecast the potential supply of surface-water deliveries, demand for groundwater pumpage, potential subsidence, and changes in groundwater storage in response to different climate-change scenarios. The detailed database on texture properties coupled with CVHM's ability to simulate the combined effects of recharge and discharge make CVHM particularly useful for assessing water-management plans, such as conjunctive water use, conservation of agriculture land, and land-use change. In the future, the CVHM could be used in conjunction with optimization models to help evaluate water-management alternatives to effectively utilize the available water resources.

  10. MX Siting Investigation. Gravity Survey - Big Smokey Valley, Nevada.

    DTIC Science & Technology

    1980-11-28

    ground- water resources. 1.2 LOCATION Big Smoky Valley is in northeastern Esmeralda and northwestern Nye counties, Nevada. The town of Tonopah, Nevada...sediments, predominantly of the Esmeralda Formation (sandstones, siltstones, and mudstones) (Kleinhampl and Ziony, 1967). The southern Toquima Range, at...Survey, Open file map, scale 1:200,000. Rush, F. E., and Schroer, C. V., 1979, Water resources of Big Smoky Valley, Landu, Nye and Esmeralda counties

  11. A brief history of oil and gas exploration in the southern San Joaquin Valley of California: Chapter 3 in Petroleum systems and geologic assessment of oil and gas in the San Joaquin Basin Province, California

    USGS Publications Warehouse

    Takahashi, Kenneth I.; Gautier, Donald L.

    2007-01-01

    The Golden State got its nickname from the Sierra Nevada gold that lured so many miners and settlers to the West, but California has earned much more wealth from so-called “black gold” than from metallic gold. The San Joaquin Valley has been the principal source for most of the petroleum produced in the State during the past 145 years. In attempting to assess future additions to petroleum reserves in a mature province such as the San Joaquin Basin, it helps to be mindful of the history of resource development. In this chapter we present a brief overview of the long and colorful history of petroleum exploration and development in the San Joaquin Valley. This chapter relies heavily upon the work of William Rintoul, who wrote extensively on the history of oil and gas exploration in California and especially in the San Joaquin Valley. No report on the history of oil and gas exploration in the San Joaquin Valley would be possible without heavily referencing his publications. We also made use of publications by Susan Hodgson and a U.S. Geological Survey Web site, Natural Oil and Gas Seeps in California (http://seeps.wr.usgs.gov/seeps/index.html), for much of the material describing the use of petroleum by Native Americans in the San Joaquin Valley. Finally, we wish to acknowledge the contribution of Don Arnot, who manages the photograph collection at the West Kern Oil Museum in Taft, California. The collection consists of more than 10,000 photographs that have been scanned and preserved in digital form on CD-ROM. Many of the historical photographs used in this paper are from that collection. Finally, to clarify our terminology, we use the term “San Joaquin Valley” when we refer to the geographical or topographical feature and the term “San Joaquin Basin” when we refer to geological province and the rocks therein.

  12. Hydrogeologic framework and estimates of groundwater storage for the Hualapai Valley, Detrital Valley, and Sacramento Valley basins, Mohave County, Arizona

    USGS Publications Warehouse

    Truini, Margot; Beard, L. Sue; Kennedy, Jeffrey; Anning, Dave W.

    2013-01-01

    We have investigated the hydrogeology of the Hualapai Valley, Detrital Valley, and Sacramento Valley basins of Mohave County in northwestern Arizona to develop a better understanding of groundwater storage within the basin fill aquifers. In our investigation we used geologic maps, well-log data, and geophysical surveys to delineate the sedimentary textures and lithology of the basin fill. We used gravity data to construct a basin geometry model that defines smaller subbasins within the larger basins, and airborne transient-electromagnetic modeled results along with well-log lithology data to infer the subsurface distribution of basin fill within the subbasins. Hydrogeologic units (HGUs) are delineated within the subbasins on the basis of the inferred lithology of saturated basin fill. We used the extent and size of HGUs to estimate groundwater storage to depths of 400 meters (m) below land surface (bls). The basin geometry model for the Hualapai Valley basin consists of three subbasins: the Kingman, Hualapai, and southern Gregg subbasins. In the Kingman subbasin, which is estimated to be 1,200 m deep, saturated basin fill consists of a mixture of fine- to coarse-grained sedimentary deposits. The Hualapai subbasin, which is the largest of the subbasins, contains a thick halite body from about 400 m to about 4,300 m bls. Saturated basin fill overlying the salt body consists predominately of fine-grained older playa deposits. In the southern Gregg subbasin, which is estimated to be 1,400 m deep, saturated basin fill is interpreted to consist primarily of fine- to coarse-grained sedimentary deposits. Groundwater storage to 400 m bls in the Hualapai Valley basin is estimated to be 14.1 cubic kilometers (km3). The basin geometry model for the Detrital Valley basin consists of three subbasins: northern Detrital, central Detrital, and southern Detrital subbasins. The northern and central Detrital subbasins are characterized by a predominance of playa evaporite and fine

  13. Mars Rover Opportunity Panorama of Marathon Valley

    NASA Image and Video Library

    2016-06-14

    "Marathon Valley" on Mars opens northeastward to a view across the floor of Endeavour Crater in this scene from the panoramic camera (Pancam) of NASA's Mars Exploration Rover Opportunity. The scene merges multiple Pancam exposures taken during the period April 16 through May 15, 2016, corresponding to sols (Martian days) 4,347 through 4,375 of Opportunity's work on Mars. It spans from north, at the left, to west-southwest, at the right. The high point in the right half of the scene is "Knudsen Ridge," which forms part of the southern edge of Marathon Valley. Portions of the northeastern and eastern rim of Endeavour crater appear on the distant horizon. Endeavour Crater is 14 miles (22 kilometers) in diameter. The fractured texture of Marathon Valley's floor is visible in the foreground. The view merges exposures taken through three of the Pancam's color filters, centered on wavelengths of 753 nanometers (near-infrared), 535 nanometers (green) and 432 nanometers (violet). It is presented in approximately true color. The rover team calls this image the mission's "Sacagawea Panorama," for the Lemhi Shoshone woman, also commemorated on U.S. dollar coins, whose assistance to the Lewis and Clark expedition helped enable its successes in 1804-1806. Many rocks and other features in Marathon Valley were informally named for members of Lewis and Clark's "Corps of Discovery" expedition. Opportunity entered Marathon Valley in July 2015. The valley's informal name was chosen because Opportunity's arrival at this point along the western rim of Endeavour Crater coincided closely with the rover surpassing marathon-footrace distance in its total driving odometry since landing on Mars in January 2004. The team's planned investigations in the valley were nearing completion when the component images for this scene were taken. http://photojournal.jpl.nasa.gov/catalog/PIA20749

  14. Sacramento Valley, CA, USA

    NASA Image and Video Library

    1973-06-22

    SL2-04-179 (22 June 1973) --- The Sacramento Valley (40.5N, 121.5W) of California is the northern extension of the Central Valley, main agriculture region of the state. Hundreds of truck farms, vineyards and orchards can be seen throughout the length and breadth of the valley which was reclaimed from the desert by means of intensive and extensive irrigation projects. Photo credit: NASA

  15. Long Valley Observatory

    USGS Publications Warehouse

    Venezky, Dina Y.; Hill, David

    2008-01-01

    The ~300-year-old lava on Paoha Island in Mono Lake was produced by the most recent eruption in the Long Valley Caldera area in east-central California. The Long Valley Caldera was formed by a massive volcanic eruption 760,000 years ago. The region is monitored by the Long Valley Observatory (LVO), one of five USGS Volcano Hazards Program observatories that monitor U.S. volcanoes for science and public safety. Learn more about the Long Valley Caldera region and LVO at http://volcanoes.usgs.gov/lvo.

  16. Recurrent Holocene faulting along the Johnson Valley portion of the 1992 Landers earthquake surface rupture

    SciTech Connect

    Lindvall, S.C. ); Rockwell, T.K. . Dept. of Geological Sciences)

    1993-04-01

    Five trenches excavated across the surface rupture associated with the 1992 Landers earthquake (M7.5) in Johnson and Homestead Valleys, Mojave Shear Zone, southern California, indicate that recurrent Holocene faulting has occurred on at least the southern Johnson Valley, Landers, and Homestead Valley faults. The stratigraphy in one trench across the southern Johnson Valley fault, which sustained 3 m of strike-slip in 1992, expresses evidence for at least three events during the Holocene, based on the presence of colluvial wedges, abrupt truncation of fault splays, stone lines and buried soils. The Landers fault, which accommodated about 2.5 m of slip in 1992, crosses Johnson Valley and allowed the rupture to continue to the north to connect with the Homestead Valley fault. Trenching across the Landers fault, south of Bodick Road, also demonstrates recurrent Holocene activity, with the penultimate event possibly being very recent. Two trenches across a secondary thrust fault along the Homestead Valley portion of the rupture records only one other possible Holocene event. Although the seismic record may not be complete along this secondary fault, the dissimilarity in rupture history with the other two faults suggested by these trenches may indicate that some of the Johnson Valley-Landers fault events may not have been broken with the Homestead Valley fault, as did the 1992 rupture.

  17. Rift Valley Fever Virus

    USDA-ARS?s Scientific Manuscript database

    Rift Valley fever virus (RVFV) is a mosquito-transmitted virus or arbovirus that is endemic in sub-Saharan Africa. In the last decade, Rift Valley fever (RVF) outbreaks have resulted in loss of human and animal life, as well as had significant economic impact. The disease in livestock is primarily a...

  18. Dry Valleys, Antarctica

    NASA Image and Video Library

    2009-11-02

    The McMurdo Dry Valleys are a row of valleys west of McMurdo Sound, Antarctica. They are so named because of their extremely low humidity and lack of snow and ice cover. This image was acquired December 8, 2002 by NASA Terra spacecraft.

  19. Down in the Valley.

    ERIC Educational Resources Information Center

    Salter, Linda Graef

    1999-01-01

    Describes the partnerships formed by West Valley Mission Community College District (California) with its surrounding Silicon Valley business community in an effort to benefit workforce development. Asserts that community colleges are uniquely positioned to provide a lifelong education that will yield a skilled workforce to meet the needs of…

  20. Down in the Valley.

    ERIC Educational Resources Information Center

    Salter, Linda Graef

    1999-01-01

    Describes the partnerships formed by West Valley Mission Community College District (California) with its surrounding Silicon Valley business community in an effort to benefit workforce development. Asserts that community colleges are uniquely positioned to provide a lifelong education that will yield a skilled workforce to meet the needs of…

  1. Ganges valley aerosol experiment.

    SciTech Connect

    Kotamarthi, V.R.; Satheesh, S.K.

    2011-08-01

    In June 2011, the Ganges Valley Aerosol Experiment (GVAX) began in the Ganges Valley region of India. The objective of this field campaign is to obtain measurements of clouds, precipitation, and complex aerosols to study their impact on cloud formation and monsoon activity in the region.

  2. Subglacial extensional fracture development and implications for Alpine Valley evolution

    NASA Astrophysics Data System (ADS)

    Leith, Kerry; Moore, Jeffrey R.; Amann, Florian; Loew, Simon

    2014-01-01

    stresses induced through exhumation and tectonic processes play a key role in the topographic evolution of alpine valleys. Using a finite difference model combining the effects of tectonics, erosion, and long-term bedrock strength, we assess the development of near-surface in situ stresses and predict bedrock behavior in response to glacial erosion in an Alpine Valley (the Matter Valley, southern Switzerland). Initial stresses are derived from the regional tectonic history, which is characterized by ongoing transtensional or extensional strain throughout exhumation of the brittle crust. We find that bedrock stresses beneath glacial ice in an initial V-shaped topography are sufficient to induce localized extensional fracturing in a zone extending laterally 600 m from the valley axis. The limit of this zone is reflected in the landscape today by a valley "shoulder," separating linear upper mountain slopes from the deep U-shaped inner valley. We propose that this extensional fracture development enhanced glacial quarrying between the valley shoulder and axis and identify a positive feedback where enhanced quarrying promoted valley incision, which in turn increased in situ stress concentrations near the valley floor, assisting erosion and further driving rapid U-shaped valley development. During interglacial periods, these stresses were relieved through brittle strain or topographic modification, and without significant erosion to reach more highly stressed bedrock, subsequent glaciation caused a reduction in differential stress and suppressed extensional fracturing. A combination of stress relief during interglacial periods, and increased ice accumulation rates in highly incised valleys, will reduce the likelihood of repeat enhanced erosion events.

  3. Field Surveys, IOC Valleys. Biological Resources Survey, Dry Lake Valley, Nevada. Volume II, Part I.

    DTIC Science & Technology

    1981-08-01

    cludes pocket gophers , ground squirrels, rabbits, and reptiles. Juniper trees that occur along the foothills of ranges are the preferred nesting sites...townsendii Pocket gopher Thomomys sp. Great Basin Kangaroo rat Dipodomys microps Southern grasshopper mouse Onychomys torridus *Deer mouse(a) Peromyscus...x x x * Whitetail Antelope Ground Squirrel (Ammospermophilus leucurus) x X Valley PocKet Gopher (Thomo~mys bottae) X X x Litte Pocket Mouse

  4. The First Prediction of a Rift Valley Fever Outbreak

    NASA Technical Reports Server (NTRS)

    Anyamba, Assaf; Chretien, Jean-Paul; Small, Jennifer; Tucker, Compton J.; Formenty, Pierre; Richardson, Jason H.; Britch, Seth C.; Schnabel, David C.; Erickson, Ralph L.; Linthicum, Kenneth J.

    2009-01-01

    El Nino/Southern Oscillation (ENSO) related anomalies were analyzed using a combination of satellite measurements of elevated sea surface temperatures, and subsequent elevated rainfall and satellite derived normalized difference vegetation index data. A Rift Valley fever risk mapping model using these climate data predicted areas where outbreaks of Rift Valley fever in humans and animals were expected and occurred in the Horn of Africa from December 2006 to May 2007. The predictions were subsequently confirmed by entomological and epidemiological field investigations of virus activity in the areas identified as at risk. Accurate spatial and temporal predictions of disease activity, as it occurred first in southern Somalia and then through much of Kenya before affecting northern Tanzania, provided a 2 to 6 week period of warning for the Horn of Africa that facilitated disease outbreak response and mitigation activities. This is the first prospective prediction of a Rift Valley fever outbreak.

  5. Implications of late Quaternary Deformation on the East Valley thrust system, Santa Clara Valley, San Francisco Bay area

    NASA Astrophysics Data System (ADS)

    Hitchcock, C. S.; Brankman, C. M.

    2001-12-01

    A series of northwest-trending reverse faults within the East Valley thrust fault system that bound the eastern margin of Santa Clara Valley are associated with the southern termination of the Hayward fault, and have been interpreted as structures that may transfer slip from the Calaveras fault to the Hayward fault. Uplift of the East Bay structural domain east of Santa Clara Valley is accommodated by this thrust fault system, which includes the Piercy, Coyote Creek, Silver Creek, Evergreen, Quimby, Berryessa, Crosley, and Warm Springs faults. Retrodeformable geologic cross sections provide constraints on the down-dip geometry and depth of interaction between faults of the East Valley thrust system and the Hayward and Calaveras fault systems. Based on the mapped geomorphic expression of the reverse faults along the base of a relatively linear, actively uplifting range front, it is possible that at least several of these faults are active, potentially seismogenic structures. However, stream terrace profiling and geomorphic map features suggest that faults within the East Valley thrust system experience repeated, minor offset and likely only rupture in secondary response to large earthquakes on the nearby Hayward and Calaveras faults and, thus, may not be fully independent seismic sources. Integration of this geomorphic and structural information has helped define the style of strain transfer at the southern end of the Hayward fault and quantified the magnitude and rate of shortening on the East Valley thrust system.

  6. Old Martian Valley

    NASA Technical Reports Server (NTRS)

    2004-01-01

    MGS MOC Release No. MOC2-578, 18 December 2003

    This Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) image shows an ancient, unnamed, martian valley in the Xanthe Terra region, located near 3.3oS, 54.9oW. This valley might have been a conduit for flowing water, but there is no way to be certain because it is so old that none of its original features have been preserved. Bright, windblown ripples are now found on the valley floor. The image covers an area 3 km (1.9 mi) wide; sunlight illuminates the scene from the left.

  7. West Valley Demonstration Project

    SciTech Connect

    Not Available

    1991-01-01

    Under the West Valley Demonstration Project Act, Public Law 96-368, liquid high-level radioactive waste stored at the Western New York Nuclear Service Center in West Valley, New York, is to be solidified (vitrified) in borosilicate glass and transported to a federal repository for geologic disposal. This waste material resulted from spent nuclear fuel reprocessing operations conducted between 1966 and 1972. Project costs are shared by the US Department of Energy (90 percent) and the New York State Energy Research and Development Authority (10 percent). The site on which the Project is located is owned by New York State. This report is an overview of West Valley's plans and accomplishments.

  8. MX Siting Investigation. Geotechnical Evaluation. Aggregate Resources Studies, Dry Lake Valley, Muleshoe Valley, Delamar Valley, Pahroc Valley, Nevada.

    DTIC Science & Technology

    1980-06-06

    Cretaceous to Pliocene in age and consist predominantly of welded and nonwelded pyro- w clastics (air falls, ash flows, ignimbrites ) of rhyolitic and...Vu Ignimbrite Valley 53 DLCDP-A53 Delamar Vu Rhyolite Valley 54 DLCDP-A54 Delamar Vu Andesite Valley 55 DLCDP-A55 Delamar Vu Rhyolitic Tuff Valley 56

  9. Flow structure and turbulence characteristics of the daytime atmosphere in a steep and narrow Alpine valley

    NASA Astrophysics Data System (ADS)

    Weigel, Andreas P.; Rotach, Mathias W.

    2004-10-01

    Aircraft measurements, radio soundings and sonic data--obtained during the MAP-Riviera field campaign in autumn 1999 in southern Switzerland--are used to investigate the flow structure, temperature profiles and turbulence characteristics of the atmosphere in a steep and narrow Alpine valley under convective conditions. On all predominantly sunny days of the intensive observation periods, a pronounced valley-wind system develops. In the southern half of the valley, the daily up-valley winds have a jet-like structure and are shifted towards the eastern slope. These up-valley winds advect potentially colder air, a process which appears to be balanced by vertical warm air advection from above. The profiles of potential temperature show that, with the onset of up-valley winds, the mixed layer consistently stops growing or--on days with very strong up-valley winds--even stabilizes almost throughout the entire valley atmosphere. This is probably due to a pronounced secondary circulation in the southern part of the valley, which induces advection of warm air from above. The secondary circulation appears to be a consequence of sharp curvature in the along-valley topography. Turbulence variables are calculated from flight legs in the along-valley direction. Turbulent kinetic energy (TKE) scales surprisingly well (i) if a TKE criterion (TKE > 0.5 m2s-2) is employed as a definition of the boundary layer height and (ii) if the 'surface fluxes'--which exhibit a substantial spatial variability--from the slope sites are used rather than those from directly beneath the profile considered. Significant site-to-site differences in incoming solar radiation seem to be the reason for this characteristic behaviour. Profiles of momentum flux--scaled with a surface friction velocity--reveal more scatter than the TKE profiles, but still show a consistent behaviour. A surprisingly strong shear in the cross-valley direction can be observed and is probably a result of the secondary circulation.

  10. Purge at West Valley

    ERIC Educational Resources Information Center

    Mack, Warren

    1977-01-01

    Tells how the adviser of the student newspaper at West Valley College (Saratoga, California) was dismissed after the newspaper published stories based on investigations into alleged wrongdoings by administration members. (GW)

  11. Mzab Valley, Algeria

    NASA Image and Video Library

    2011-03-24

    Located 600 km south of Algiers, Algeria in the heart of the Sahara Desert, the five ksour fortified villages of the MZab Valley form an extraordinarily homogenous ensemble in this image captured by NASA Terra spacecraft.

  12. Death Valley, California

    NASA Image and Video Library

    2009-06-29

    Death Valley, Calif., has the lowest point in North America, Badwater at 85.5 meters 282 feet below sea level. It is also the driest and hottest location in North America. This image is from NASA Terra spacecraft.

  13. California: Diamond Valley

    Atmospheric Science Data Center

    2014-05-15

    ... water storage capacity. In addition to routine water management, Diamond Valley Lake is designed to provide protection against ... to stand out prominently by taking advantage of the strong change in brightness between the two view angles and the contrasting angular ...

  14. Geothermal hydrology of Warner Valley, Oregon: a reconnaissance study

    SciTech Connect

    Sammel, E.A.; Craig, R.W.

    1981-01-01

    Warner Valley and its southern extension, Coleman Valley, are two of several high-desert valleys in the Basin and Range province of south-central Oregon that contain thermal waters. At least 20 thermal springs, defined as having temperatures of 20/sup 0/C or more, issue from Tertiary basaltic flows and tuffs in and near the valleys. Many shallow wells also produce thermal waters. The highest measured temperature is 127/sup 0/C, reported from a well known as Crump geyser, at a depth of 200 meters. The hottest spring, located near Crump geyser, has a surface temperature of 78/sup 0/C. The occurrence of these thermal waters is closely related to faults and fault intersections in the graben and horst structure of the valleys. Chemical analyses show that the thermal waters are of two types: sodium chloride and sodium bicarbonate waters. The warmer waters are likely to have higher concentrations of sodium and chloride, as well as sulfate, silica, and dissolved solids, than the cooler waters. Chemical indicators show that the geothermal system is a hot-water rather than a vapor-dominated system. Conductive heat flow in areas of the valley unaffected by hydrothermal convection is probably about 75 milliwatts per square meter. The normal thermal gradient in valley-fill deposits in these areas may be about 40/sup 0/C per kilometer. Extensive areas underlain by thermal ground water occur near Crump geyser and Fisher Hot Spring.

  15. Geothermal hydrology of Warner Valley, Oregon: a reconnaissance study

    SciTech Connect

    Sammel, E.A.; Craig, R.W.

    1981-01-01

    Warner Valley and its southern extension, Coleman Valley, are two of several high-desert valleys in the Basin and Range province of south-central Oregon that contain thermal waters. At least 20 thermal springs, defined as having temperatures of 20/sup 0/C or more, issue from Tertiary basaltic flows and tuffs in and near the valleys. Many shallow wells also produce thermal waters. The highest measured temperature is 127/sup 0/C, reported from a well known as Crump geyser, at a depth of 200 meters. The hottest spring, located near Crump geyser, has a surface temperature of 78/sup 0/C. The occurrence of these thermal waters is closely related to faults and fault intersections in the graben and horst structure of the valleys. Chemical analyses show that the thermal waters are of two types: sodium chloride and sodium bicarbonate waters. Chemical indicators show that the geothermal system is a hot-water rather than a vapor-dominated system. Conductive heat flow in areas of the valley unaffected by hydrothermal convection is probably about 75 milliwatts per square meter. The normal thermal gradient in valley-fill dpeosits in these areas may be about 40/sup 0/C per kilometer. Geothermometers and mixing models indicate that temperatures of equilibration are at least 170/sup 0/C for the thermal components of the hotter waters. The size and location of geothermal reservoirs are unknown.

  16. NV PFA - Steptoe Valley

    SciTech Connect

    Jim Faulds

    2015-10-29

    All datasets and products specific to the Steptoe Valley model area. Includes a packed ArcMap project (.mpk), individually zipped shapefiles, and a file geodatabase for the northern Steptoe Valley area; a GeoSoft Oasis montaj project containing GM-SYS 2D gravity profiles along the trace of our seismic reflection lines; a 3D model in EarthVision; spreadsheet of links to published maps; and spreadsheets of well data.

  17. Analysis of the Cache Valley deposits in Illinois and implications regarding the late Pleistocene-Holocene development of the Ohio River Valley

    NASA Astrophysics Data System (ADS)

    Esling, Steven P.; Hughes, W. Brian; Graham, Richard C.

    1989-05-01

    The Cache Valley, a prominent physiographic feature connecting the Ohio and Mississippi river valleys across southern Illinois, at one time probably carried discharge from the ancestral Ohio River. The valley is now occupied by two small streams. Core samples from 27 boreholes in the Cache Valley and 25 on the adjoining uplands were described and analyzed in terms of clay mineralogy and texture. The Holocene surficial deposits of the Cache Valley contain predominantly silt with high percentages of expandable and kaolinite + chlorite clay minerals in the clay fraction, a characteristic of the local upland provenance. The surfcial deposits are underlain by predominantly sandy sediment containing a high percentage of illite (35%-70%) relative to the expandable and kaolinite + chlorite clay minerals, a characteristic of Ohio River outwash. Clay content of sediment at depth at the mouths of valleys tributary to the Cache Valley suggests that these deposits accumulated within quiet water impounded by sediment dams within the Cache Valley as the ancestral Ohio River aggraded during late Wisconsinan time. Physical relations between tributary deposits and main valley deposits, plus radiocarbon dates on organic material recovered from the boreholes, suggest that the Ohio River abondoned the Cache Valley after 25ka, but before 8 ka.

  18. Green Valley Galaxies

    NASA Astrophysics Data System (ADS)

    Salim, S.

    2014-12-01

    The "green valley" is a wide region separating the blue and the red peaks in the ultraviolet-optical color magnitude diagram, first revealed using GALEX UV photometry. The term was coined by Christopher Martin (Caltech), in 2005. Green valley highlights the discriminating power of UV to very low relative levels of ongoing star formation, to which the optical colors, including u-r, are insensitive. It corresponds to massive galaxies below the star-forming, "main" sequence, and therefore represents a critical tool for the study of the quenching of star formation and its possible resurgence in otherwise quiescent galaxies. This article reviews the results pertaining to (predominanlty disk) morphology, structure, environment, dust content and gas properties of green valley galaxies in the local universe. Their relationship to AGN is also discussed. Attention is given to biases emerging from defining the "green valley" using optical colors. We review various evolutionary scenarios and we present evidence for a new one, the quasi-static view of the green valley, in which the majority (but not all) of galaxies currently in the green valley were only partially quenched in the distant past and now participate in a slow cosmic decline of star formation, which also drives down the activity on the main sequence, presumably as a result of the dwindling accretion/cooling onto galaxy disks. This emerging synthetic picture is based on the findings from Fang et al. (2012), Salim et al. (2012) and Martin et al. (2007), as well as other results.

  19. Grizzly Valley fault system, Sierra Valley, CA

    USGS Publications Warehouse

    Gold, Ryan; Stephenson, William; Odum, Jack; Briggs, Rich; Crone, Anthony; Angster, Steve

    2012-01-01

    The Grizzly Valley fault system (GVFS) strikes northwestward across Sierra Valley, California and is part of a network of active, dextral strike-slip faults in the northern Walker Lane (Figure 1). To investigate Quaternary motion across the GVFS, we analyzed high-resolution (0.25 m) airborne LiDAR data (Figure 2) in combination with six, high-resolution, P-wave, seismic-reflection profiles [Gold and others, 2012]. The 0.5- to 2.0-km-long seismic-reflection profiles were sited orthogonal to suspected tectonic lineaments identified from previous mapping and our analysis of airborne LiDAR data. To image the upper 400–700 m of subsurface stratigraphy of Sierra Valley (Figure 3), we used a 230-kg accelerated weight drop source. Geophone spacing ranged from 2 to 5 m and shots were co-located with the geophones. The profiles reveal a highly reflective, deformed basal marker that we interpret to be the top of Tertiary volcanic rocks, overlain by a 120- to 300-m-thick suite of subhorizontal reflectors we interpret as Plio-Pleistocene lacustrine deposits. Three profiles image the principle active trace of the GVFS, which is a steeply dipping fault zone that offsets the volcanic rocks and the basin fill (Figures 4 & 5).

  20. Analysis of crater valleys, Noachis Terra, Mars: Evidence of fluvial and glacial processes

    NASA Astrophysics Data System (ADS)

    Hobbs, S. W.; Clarke, J. D. A.; Paull, D. J.

    2016-05-01

    The precise mechanism for the formation and evolution of crater valley networks in the Martian southern highlands remains under debate, with precipitation, groundwater flow, and melting induced by impact being suggested. We studied valley networks within four craters of the Noachis Terra highlands that were representative of similar features in Noachis Terra and where orbital data existed for analysis in order to characterise their morphology and infer possible processes involved in their formation and evolution. We found evidence for valleys carved by liquid water and ice-related processes. This included strong evidence of liquid water-based valley formation through melting of ice-rich deposits throughout our study area, suggesting an alternative to previously suggested rainfall or groundwater-based scenarios. The location of these valleys on steeply sloping crater walls, as opposed to the shallow slopes of the highlands where Martian valleys are typically found, suggested that our 'fluvial' valleys had not evolved a more structured fluvial morphology as valley networks found on the Martian plains. Our studied valleys' association with ice-rich material and abundant evidence for erosion caused by downslope flow of ice-rich material are consistent with a cold, wet Mars hypothesis where accumulation, flow, and melting of ice have been dominant factors in eroding crater valleys. Additionally, analysis of valley morphology with slope and aspect suggested a greater dependence on local geology and presence of volatiles than larger valley networks, though ice-related valleys were consistently wider for their length than valleys assessed as fluvial carved. We assessed that local conditions such as climate, geology, and availability of ice-rich material played a major role in the erosion of crater valleys at our study site.

  1. Southern Appalachian Regional Seismic Network

    SciTech Connect

    Chiu, S.C.C.; Johnston, A.C.; Chiu, J.M.

    1994-08-01

    The seismic activity in the southern Appalachian area was monitored by the Southern Appalachian Regional Seismic Network (SARSN) since late 1979 by the Center for Earthquake Research and Information (CERI) at Memphis State University. This network provides good spatial coverage for earthquake locations especially in east Tennessee. The level of activity concentrates more heavily in the Valley and Ridge province of eastern Tennessee, as opposed to the Blue Ridge or Inner Piedmont. The large majority of these events lie between New York - Alabama lineament and the Clingman/Ocoee lineament, magnetic anomalies produced by deep-seated basement structures. Therefore SARSN, even with its wide station spacing, has been able to define the essential first-order seismological characteristics of the Southern Appalachian seismic zone. The focal depths of the southeastern U.S. earthquakes concentrate between 8 and 16 km, occurring principally beneath the Appalachian overthrust. In cross-sectional views, the average seismicity is shallower to the east beneath the Blue Ridge and Piedmont provinces and deeper to the west beneath the Valley and Ridge and the North American craton. Results of recent focal mechanism studies by using the CERI digital earthquake catalog between October, 1986 and December, 1991, indicate that the basement of the Valley and Ridge province is under a horizontal, NE-SW compressive stress. Right-lateral strike-slip faulting on nearly north-south fault planes is preferred because it agrees with the trend of the regional magnetic anomaly pattern.

  2. Earthquakes in Tuhinj Valley (Slovenia) In 1840

    NASA Astrophysics Data System (ADS)

    Cecić, Ina

    2015-04-01

    A less known damaging earthquake in southern part of Kamnik-Savinja Alps, Slovenia, in 1840 is described. The main shock was on 27 August 1840 with the epicentre in Tuhinj Valley. The maximum intensity was VII EMS-98 in Ljubljana, Slovenia, and in Eisenkappel, Austria. It was felt as far as Venice, Italy, 200 km away. The macroseismic magnitude of the main shock, estimated from the area of intensity VI EMS-98, was 5.0. The effects of the main shock and its aftershocks are described, and an earthquake catalogue for Slovenia in 1840 is provided. Available primary sources (newspaper articles) are presented.

  3. The development of a deep-towed gravity meter, and its use in marine geophysical surveys of offshore southern California and an airborne laser altimeter survey of Long Valley, California

    NASA Astrophysics Data System (ADS)

    Ridgway, Jeffrey R.

    Marine Gravity is presently measured on the sea surface and on the sea floor. Surface measurements suffer from a loss of resolution, and seafloor measurements are slow to perform. The TOWDOG was created to operate near the seafloor but have a faster data recovery rate than seafloor measurements. It is a Lacoste and Romberg gravity meter, mounted inside a pressure case, and placed upon a platform which is stable while being towed. The instrument's depth is determined by pressure measurements. Its horizontal position is calculated using a dynamic model of the towing cable. The first deployment of the instrument was in the San Diego Trough, a sedimentary basin offshore San Diego. Multiple gravity tracks were obtained at a depth of 935 meters. The rms repeatability between coincident tracks is 0.4 mGal. The inter-track gravity signal is coherent for wavelengths greater than 640 meters. A 1-km-wide seafloor depression in the Trough generates a 0.7 mGal gravity anomaly, which is seen in the data when 3 tracks are stacked. The goal of the San Diego Trough survey was to determine if a significant density contrast exists across the basin's central axial fault. The survey reveals that no discernible contrast exists across the near-surface part of the fault. Two-dimensional gravity modeling constrained by seismic reflection profiles yields a depth to basement of 3.8 to 4.8 km below sea-level. A 3-component model (younger sediment, older, sedimentary rocks, and acoustic basement), best fits the seismic and gravity data. The laser altimeter survey of Long Valley, California tests the capabilities of an aircraft-mounted laser in monitoring time-varying uplift of a resurgent volcanic dome. The system can profile a lake surface with an r.m.s. repeatability of 3-5 cm, and can detect time-varying height changes of the lake level of 5 cm per day. This should be sufficiently accurate to detect yearly uplift of 4 cm per year, as is occurring at Long Valley. The detection of such

  4. The geochemistry of groundwater resources in the Jordan Valley: The impact of the Rift Valley brines

    USGS Publications Warehouse

    Farber, E.; Vengosh, A.; Gavrieli, I.; Marie, A.; Bullen, T.D.; Mayer, B.; Polak, A.; Shavit, U.

    2007-01-01

    The chemical composition of groundwater in the Jordan Valley, along the section between the Sea of Galilee and the Dead Sea, is investigated in order to evaluate the origin of the groundwater resources and, in particular, to elucidate the role of deep brines on the chemical composition of the regional groundwater resources in the Jordan Valley. Samples were collected from shallow groundwater in research boreholes on two sites in the northern and southern parts of the Jordan Valley, adjacent to the Jordan River. Data is also compiled from previous published studies. Geochemical data (e.g., Br/Cl, Na/Cl and SO4/Cl ratios) and B, O, Sr and S isotopic compositions are used to define groundwater groups, to map their distribution in the Jordan valley, and to evaluate their origin. The combined geochemical tools enabled the delineation of three major sources of solutes that differentially affect the quality of groundwater in the Jordan Valley: (1) flow and mixing with hypersaline brines with high Br/Cl (>2 ?? 10-3) and low Na/Cl (<0.8) ratios; (2) dissolution of highly soluble salts (e.g., halite, gypsum) in the host sediments resulting in typically lower Br/Cl signal (<2 ?? 10-3); and (3) recharge of anthropogenic effluents, primarily derived from evaporated agricultural return flow that has interacted (e.g., base-exchange reactions) with the overlying soil. It is shown that shallow saline groundwaters influenced by brine mixing exhibit a north-south variation in their Br/Cl and Na/Cl ratios. This chemical trend was observed also in hypersaline brines in the Jordan valley, which suggests a local mixing process between the water bodies. ?? 2007 Elsevier Ltd. All rights reserved.

  5. 14. ALABAMA, SUMTER CO., EPES RAILROAD BRIDGE Southern RR at ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    14. ALABAMA, SUMTER CO., EPES RAILROAD BRIDGE Southern RR at Epes Alabama Great Southern RR bridge. View from S. Copy of photo taken in 1922 by Jack Donnell, Columbus, Ms. Sarcone Photography, Columbus, Ms., Sep 1978. - Bridges of the Upper Tombigbee River Valley, Cochrane, Pickens County, AL

  6. Prediction of a Rift Valley fever outbreak

    PubMed Central

    Anyamba, Assaf; Chretien, Jean-Paul; Small, Jennifer; Tucker, Compton J.; Formenty, Pierre B.; Richardson, Jason H.; Britch, Seth C.; Schnabel, David C.; Erickson, Ralph L.; Linthicum, Kenneth J.

    2009-01-01

    El Niño/Southern Oscillation related climate anomalies were analyzed by using a combination of satellite measurements of elevated sea-surface temperatures and subsequent elevated rainfall and satellite-derived normalized difference vegetation index data. A Rift Valley fever (RVF) risk mapping model using these climate data predicted areas where outbreaks of RVF in humans and animals were expected and occurred in the Horn of Africa from December 2006 to May 2007. The predictions were subsequently confirmed by entomological and epidemiological field investigations of virus activity in the areas identified as at risk. Accurate spatial and temporal predictions of disease activity, as it occurred first in southern Somalia and then through much of Kenya before affecting northern Tanzania, provided a 2 to 6 week period of warning for the Horn of Africa that facilitated disease outbreak response and mitigation activities. To our knowledge, this is the first prospective prediction of a RVF outbreak. PMID:19144928

  7. Fretted Terrain Valleys

    NASA Technical Reports Server (NTRS)

    2004-01-01

    30 October 2004 This Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) image shows shallow tributary valleys in the Ismenius Lacus fretted terrain region of northern Arabia Terra. These valleys exhibit a variety of typical fretted terrain valley wall and floor textures, including a lineated, pitted material somewhat reminiscent of the surface of a brain. Origins for these features are still being debated within the Mars science community; there are no clear analogs to these landforms on Earth. This image is located near 39.9oN, 332.1oW. The picture covers an area about 3 km (1.9 mi) wide. Sunlight illuminates the scene from the lower left.

  8. Valley near Olympus

    NASA Technical Reports Server (NTRS)

    2003-01-01

    MGS MOC Release No. MOC2-539, 9 November 2003

    A suite of channels and valleys are carved into the plains southeast of the martian volcano, Olympus Mons. This Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) image shows an example located near 16.5oN, 124.8oW. Whether the valley was cut by water is unknown. Today it is dry, has dust-covered wind ripples on the floor of the innermost channel, and small craters have formed here and there on the valley terrain. This picture covers an area 3 km (1.9 mi) wide and is illuminated by sunlight from the left.

  9. Fretted Terrain Valleys

    NASA Technical Reports Server (NTRS)

    2004-01-01

    30 October 2004 This Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) image shows shallow tributary valleys in the Ismenius Lacus fretted terrain region of northern Arabia Terra. These valleys exhibit a variety of typical fretted terrain valley wall and floor textures, including a lineated, pitted material somewhat reminiscent of the surface of a brain. Origins for these features are still being debated within the Mars science community; there are no clear analogs to these landforms on Earth. This image is located near 39.9oN, 332.1oW. The picture covers an area about 3 km (1.9 mi) wide. Sunlight illuminates the scene from the lower left.

  10. Geohydrology of the Unconsolidated Valley-Fill Aquifer in the Meads Creek Valley, Schuyler and Steuben Counties, New York

    USGS Publications Warehouse

    Miller, Todd S.; Bugliosi, Edward F.; Reddy, James E.

    2008-01-01

    The Meads Creek valley encompasses 70 square miles of predominantly forested uplands in the upper Susquehanna River drainage basin. The valley, which was listed as a Priority Waterbody by the New York State Department of Environmental Conservation in 2004, is prone to periodic flooding, mostly in its downstream end, where development is occurring most rapidly. Hydraulic characteristics of the unconsolidated valley-fill aquifer were evaluated, and seepage rates in losing and gaining tributaries were calculated or estimated, in an effort to delineate the aquifer geometry and identify the factors that contribute to flooding. Results indicated that (1) Meads Creek gained about 61 cubic feet of flow per second (about 6.0 cubic feet per second per mile of stream channel) from ground-water discharge and inflow from tributaries in its 10.2-mile reach between the northernmost and southernmost measurement sites; (2) major tributaries in the northern part of the valley are not significant sources of recharge to the aquifer; and (3) major tributaries in the central and southern part of the valley provide recharge to the aquifer. The ground-water portion of streamflow in Meads Creek (excluding tributary inflow) was 11.3 cubic feet per second (ft3/s) in the central part of the valley and 17.2 ft3/s in the southern part - a total of 28.5 ft3/s. Ground-water levels were measured in 29 wells finished in unconfined deposits for construction of a potentiometric-surface map to depict directions of ground-water flow within the valley. In general, ground water flows from the edges of the valley toward Meads Creek and ultimately discharges to it. The horizontal hydraulic gradient for the entire 12-mile-long aquifer averages about 30 feet per mile, whereas the gradient in the southern fourth of the valley averages about half that - about 17 feet per mile. A water budget for the aquifer indicated that 28 percent of recharge was derived from precipitation that falls on the aquifer, 32

  11. Hydrogeology of the carbonate rocks of the Lebanon Valley, Pennsylvania

    USGS Publications Warehouse

    Meisler, Harold

    1963-01-01

    The Lebanon Valley, which is part of the Great Valley in southeastern Pennsylvania, is underlain by carbonate rocks in the southern part and by shale in the northern part. The carbonate rocks consist of alternating beds of limestone and dolomite of Cambrian and Ordovician age. Although the beds generally dip to the south, progressively younger beds crop out to the north, because the rocks are overturned. The stratigraphic units, from oldest to youngest, are: the Buffalo Springs Formation, Snitz Creek, Schaefferstown, Millbach, and Richland Formations of the Conococheague Group; the Stonehenge, Rickenbach, Epler, and Ontelaunee Formations of the Beekmantown Group; and the Annville, Myerstown, and Hershey Limestones.

  12. Diversity of micro-fungi in an Antarctic dry valley.

    PubMed

    Baublis, J A; Wharton, R A; Volz, P A

    1991-01-01

    The fungal microflora of a dry valley in Southern Victoria Land near McMurdo Sound, Antarctica, was investigated. Samples were collected from introduced objects such as a mummified penguin and spent chewing tobacco in addition to the sparse soil found in rock fissures, isolated moss colonies, shoreline deposit materials, CaCO3 precipitates, and microbial mat debris obtained from the frozen surface of the lake in the basin of Taylor Valley. Using conventional media and techniques, all collection sites yielded populations of yeasts and filamentous fungi. Water samples and live microbial mats from beneath the lake ice yielded species of fungi along with an abundance of bacteria.

  13. Diversity of micro-fungi in an Antarctic dry valley

    NASA Technical Reports Server (NTRS)

    Baublis, J. A.; Wharton, R. A. Jr; Volz, P. A.; Wharton RA, J. r. (Principal Investigator)

    1991-01-01

    The fungal microflora of a dry valley in Southern Victoria Land near McMurdo Sound, Antarctica, was investigated. Samples were collected from introduced objects such as a mummified penguin and spent chewing tobacco in addition to the sparse soil found in rock fissures, isolated moss colonies, shoreline deposit materials, CaCO3 precipitates, and microbial mat debris obtained from the frozen surface of the lake in the basin of Taylor Valley. Using conventional media and techniques, all collection sites yielded populations of yeasts and filamentous fungi. Water samples and live microbial mats from beneath the lake ice yielded species of fungi along with an abundance of bacteria.

  14. New vectors of Rift Valley fever in West Africa.

    PubMed Central

    Fontenille, D.; Traore-Lamizana, M.; Diallo, M.; Thonnon, J.; Digoutte, J. P.; Zeller, H. G.

    1998-01-01

    After an outbreak of Rift Valley fever in Southern Mauritania in 1987, entomologic studies were conducted in a bordering region in Sénégal from 1991 to 1996 to identify the sylvatic vectors of Rift Valley fever virus. The virus was isolated from the floodwater mosquitoes Aedes vexans and Ae. ochraceus. In 1974 and 1983, the virus had been isolated from Ae. dalzieli. Although these vectors differ from the main vectors in East and South Africa, they use the same type of breeding sites and also feed on cattle and sheep. Although enzootic vectors have now been identified in West Africa, the factors causing outbreaks remain unclear. PMID:9621201

  15. New vectors of Rift Valley fever in West Africa.

    PubMed

    Fontenille, D; Traore-Lamizana, M; Diallo, M; Thonnon, J; Digoutte, J P; Zeller, H G

    1998-01-01

    After an outbreak of Rift Valley fever in Southern Mauritania in 1987, entomologic studies were conducted in a bordering region in Sénégal from 1991 to 1996 to identify the sylvatic vectors of Rift Valley fever virus. The virus was isolated from the floodwater mosquitoes Aedes vexans and Ae. ochraceus. In 1974 and 1983, the virus had been isolated from Ae. dalzieli. Although these vectors differ from the main vectors in East and South Africa, they use the same type of breeding sites and also feed on cattle and sheep. Although enzootic vectors have now been identified in West Africa, the factors causing outbreaks remain unclear.

  16. Diversity of micro-fungi in an Antarctic dry valley

    NASA Technical Reports Server (NTRS)

    Baublis, J. A.; Wharton, R. A. Jr; Volz, P. A.; Wharton RA, J. r. (Principal Investigator)

    1991-01-01

    The fungal microflora of a dry valley in Southern Victoria Land near McMurdo Sound, Antarctica, was investigated. Samples were collected from introduced objects such as a mummified penguin and spent chewing tobacco in addition to the sparse soil found in rock fissures, isolated moss colonies, shoreline deposit materials, CaCO3 precipitates, and microbial mat debris obtained from the frozen surface of the lake in the basin of Taylor Valley. Using conventional media and techniques, all collection sites yielded populations of yeasts and filamentous fungi. Water samples and live microbial mats from beneath the lake ice yielded species of fungi along with an abundance of bacteria.

  17. Rift Valley fever vaccines

    PubMed Central

    Ikegami, Tetsuro; Makino, Shinji

    2009-01-01

    Rift Valley fever virus (RVFV), which belongs to the genus Phlebovirus, family Bunyaviridae, is a negative-stranded RNA virus carrying a tripartite RNA genome. RVFV is transmitted by mosquitoes and causes large outbreaks among ruminants and humans in Africa and the Arabian Peninsula. Human patients develop an acute febrile illness, followed by a fatal hemorrhagic fever, encephalitis or ocular diseases, whereas ruminants experience abortions during outbreak. Effective vaccination of both humans and ruminants is the best approach to control Rift Valley fever. This article summarizes the development of inactivated RVFV vaccine, live attenuated vaccine, and other new generation vaccines. PMID:19837291

  18. Session: Long Valley Exploratory Well

    SciTech Connect

    Tennyson, George P. Jr.; Finger, John T.; Eichelberger, John C.; Hickox, Charles E.

    1992-01-01

    This session at the Geothermal Energy Program Review X: Geothermal Energy and the Utility Market consisted of four presentations: ''Long Valley Exploratory Well - Summary'' by George P. Tennyson, Jr.; ''The Long Valley Well - Phase II Operations'' by John T. Finger; ''Geologic results from the Long Valley Exploratory Well'' by John C. Eichelberger; and ''A Model for Large-Scale Thermal Convection in the Long Valley Geothermal Region'' by Charles E. Hickox.

  19. Groundwater Availability of the Central Valley Aquifer, California

    USGS Publications Warehouse

    Faunt, Claudia C.

    2009-01-01

    California's Central Valley covers about 20,000 square miles and is one of the most productive agricultural regions in the world. More than 250 different crops are grown in the Central Valley with an estimated value of $17 billion per year. This irrigated agriculture relies heavily on surface-water diversions and groundwater pumpage. Approximately one-sixth of the Nation's irrigated land is in the Central Valley, and about one-fifth of the Nation's groundwater demand is supplied from its aquifers. The Central Valley also is rapidly becoming an important area for California's expanding urban population. Since 1980, the population of the Central Valley has nearly doubled from 2 million to 3.8 million people. The Census Bureau projects that the Central Valley's population will increase to 6 million people by 2020. This surge in population has increased the competition for water resources within the Central Valley and statewide, which likely will be exacerbated by anticipated reductions in deliveries of Colorado River water to southern California. In response to this competition for water, a number of water-related issues have gained prominence: conservation of agricultural land, conjunctive use, artificial recharge, hydrologic implications of land-use change, and effects of climate variability. To provide information to stakeholders addressing these issues, the USGS Groundwater Resources Program made a detailed assessment of groundwater availability of the Central Valley aquifer system, that includes: (1) the present status of groundwater resources; (2) how these resources have changed over time; and (3) tools to assess system responses to stresses from future human uses and climate variability and change. This effort builds on previous investigations, such as the USGS Central Valley Regional Aquifer System and Analysis (CV-RASA) project and several other groundwater studies in the Valley completed by Federal, State and local agencies at differing scales. The

  20. Smart Valley Infrastructure.

    ERIC Educational Resources Information Center

    Maule, R. William

    1994-01-01

    Discusses prototype information infrastructure projects in northern California's Silicon Valley. The strategies of the public and private telecommunications carriers vying for backbone services and industries developing end-user infrastructure technologies via office networks, set-top box networks, Internet multimedia, and "smart homes"…

  1. DESOLATION VALLEY WILDERNESS, CALIFORNIA.

    USGS Publications Warehouse

    Dodge, F.C.W.; Fillo, P.V.

    1984-01-01

    The Desolation Valley Wilderness covers an area of 101 sq mi in El Dorado County, California, near the southwestern shore of Lake Tahoe. A mineral survey disclosed the presence of a small mineralized area with demonstrated gold resources. Exploratory drilling is necessary before the resource potential of gold-bearing rocks can be assessed.

  2. Boyne Valley Tombs

    NASA Astrophysics Data System (ADS)

    Prendergast, Frank

    The passage tombs of the Boyne Valley exhibit the greatest level of development of the megalithic tomb building tradition in Ireland in terms of their morphology, embellishment, burial tradition, grave goods, clustering, and landscape siting. This section examines these characteristics and gives a summary archaeoastronomical appraisal of their orientation and detected astronomical alignment.

  3. Echoes of Spring Valley.

    ERIC Educational Resources Information Center

    Boyken, J. Clarine J.

    Designed to preserve the rich heritage of the rural school system which passed from the education scene in the 1930's and 1940's, this narrative, part history and part nostalgia, describes the author's own elementary education and the secure community life centered in the one room Spring Valley School in Hamilton County, Iowa, in the early decades…

  4. Rift Valley Fever Review

    USDA-ARS?s Scientific Manuscript database

    Rift Valley fever (RVF) is a disease of animals and humans that occurs in Africa and the Arabian Peninsula. A Phlebovirus in the family Bunyaviridae causes the disease that is transmitted by mosquitoes. Epidemics occur during years of unusually heavy rainfall that assessment models are being develo...

  5. Mars Marathon Valley Overlook

    NASA Image and Video Library

    2015-03-23

    This view from NASA's Mars Exploration Rover Opportunity shows part of "Marathon Valley," a destination on the western rim of Endeavour Crater, as seen from an overlook north of the valley. The scene spans from east, at left, to southeast. It combines four pointings of the rover's panoramic camera (Pancam) on March 13, 2015, during the 3,958th Martian day, or sol, of Opportunity's work on Mars. The rover team selected Marathon Valley as a science destination because observations of this location using the Compact Reconnaissance Imaging Spectrometer for Mars (CRISM) instrument on NASA's Mars Reconnaissance Orbiter yielded evidence of clay minerals, a clue to ancient wet environments. By the time Opportunity explores Marathon Valley, the rover will have exceeded a total driving distance equivalent to an Olympic marathon. Opportunity has been exploring the Meridiani Planum region of Mars since January 2004. This version of the image is presented in approximate true color by combining exposures taken through three of the Pancam's color filters at each of the four camera pointings, using filters centered on wavelengths of 753 nanometers (near-infrared), 535 nanometers (green) and 432 nanometers (violet). http://photojournal.jpl.nasa.gov/catalog/PIA19151

  6. Smart Valley Infrastructure.

    ERIC Educational Resources Information Center

    Maule, R. William

    1994-01-01

    Discusses prototype information infrastructure projects in northern California's Silicon Valley. The strategies of the public and private telecommunications carriers vying for backbone services and industries developing end-user infrastructure technologies via office networks, set-top box networks, Internet multimedia, and "smart homes"…

  7. Fretted Terrain Valley

    NASA Technical Reports Server (NTRS)

    2005-01-01

    4 May 2005 This Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) image shows the floor of a fretted terrain valley in the Coloe Fossae region. Valleys found at north middle latitudes, such as this one, often have odd linear features on them. When seen at much lower resolution by the Viking Orbiters in the late 1970s, investigators assumed that the linear features indicated flow of ice or ice-rich debris, as might occur in a glacier or rock glacier. MOC images show little evidence to support the notion that these materials flow; indeed, similar ridges occur in closed valleys, from which nothing can flow. This picture shows a close-up of one such closed valley.

    Location near: 35.3oN, 303.1oW Image width: 3 km (1.9 mi) Illumination from: lower left Season: Northern Summer

  8. Echoes of Spring Valley.

    ERIC Educational Resources Information Center

    Boyken, J. Clarine J.

    Designed to preserve the rich heritage of the rural school system which passed from the education scene in the 1930's and 1940's, this narrative, part history and part nostalgia, describes the author's own elementary education and the secure community life centered in the one room Spring Valley School in Hamilton County, Iowa, in the early decades…

  9. Bringing Silicon Valley inside.

    PubMed

    Hamel, G

    1999-01-01

    In 1998, Silicon Valley companies produced 41 IPOs, which by January 1999 had a combined market capitalization of $27 billion--that works out to $54,000 in new wealth creation per worker in a single year. Multiply the number of employees in your company by $54,000. Did your business create that much new wealth last year? Half that amount? It's not a group of geniuses generating such riches. It's a business model. In Silicon Valley, ideas, capital, and talent circulate freely, gathering into whatever combinations are most likely to generate innovation and wealth. Unlike most traditional companies, which spend their energy in resource allocation--a system designed to avoid failure--the Valley operates through resource attraction--a system that nurtures innovation. In a traditional company, people with innovative ideas must go hat in hand to the guardians of the old ideas for funding and for staff. But in Silicon Valley, a slew of venture capitalists vie to attract the best new ideas, infusing relatively small amounts of capital into a portfolio of ventures. And talent is free to go to the companies offering the most exhilarating work and the greatest potential rewards. It should actually be easier for large, traditional companies to set up similar markets for capital, ideas, and talent internally. After all, big companies often already have extensive capital, marketing, and distribution resources, and a first crack at the talent in their own ranks. And some of them are doing it. The choice is yours--you can do your best to make sure you never put a dollar of capital at risk, or you can tap into the kind of wealth that's being created every day in Silicon Valley.

  10. Groundwater quality in the Owens Valley, California

    USGS Publications Warehouse

    Dawson, Barbara J. Milby; Belitz, Kenneth

    2012-01-01

    Groundwater provides more than 40 percent of California’s drinking water. To protect this vital resource, the State of California created the Groundwater Ambient Monitoring and Assessment (GAMA) Program. The Priority Basin Project of the GAMA Program provides a comprehensive assessment of the State’s groundwater quality and increases public access to groundwater-quality information. Owens Valley is one of the study areas being evaluated. The Owens study area is approximately 1,030 square miles (2,668 square kilometers) and includes the Owens Valley groundwater basin (California Department of Water Resources, 2003). Owens Valley has a semiarid to arid climate, with average annual rainfall of about 6 inches (15 centimeters). The study area has internal drainage, with runoff primarily from the Sierra Nevada draining east to the Owens River, which flows south to Owens Lake dry lakebed at the southern end of the valley. Beginning in the early 1900s, the City of Los Angeles began diverting the flow of the Owens River to the Los Angeles Aqueduct, resulting in the evaporation of Owens Lake and the formation of the current Owens Lake dry lakebed. Land use in the study area is approximately 94 percent (%) natural, 5% agricultural, and 1% urban. The primary natural land cover is shrubland. The largest urban area is the city of Bishop (2010 population of 4,000). Groundwater in this basin is used for public and domestic water supply and for irrigation. The main water-bearing units are gravel, sand, silt, and clay derived from surrounding mountains. Recharge to the groundwater system is primarily runoff from the Sierra Nevada, and by direct infiltration of irrigation. The primary sources of discharge are pumping wells, evapotranspiration, and underflow to the Owens Lake dry lakebed. The primary aquifers in Owens Valley are defined as those parts of the aquifers corresponding to the perforated intervals of wells listed in the California Department of Public Health database

  11. Formation of Pedogenic Carbonates in the Semi-arid Rio Grande Valley: Insights from Carbon, Major elements, and U-series isotopes in Natural and Agricultural Soils of Southern New Mexico and Western Texas

    NASA Astrophysics Data System (ADS)

    Nyachoti, S. K.; Ma, L.; Jin, L.; Tweedie, C. E.

    2013-12-01

    Accumulation of pedogenic carbonates in arid and semi-arid soils affects soil porosity, water infiltration, and global carbon cycle. We investigate formation rates of these carbonates under different land uses in the semi-arid Rio Grande valley using mineralogy, concentrations of major elements (including C), and U-series isotopes. Our study sites include one alfalfa farm (Alfalfa) at El Paso, TX under frequent irrigation with saline water from the Rio Grande River, and one natural shrub field under natural rainfall conditions at the USDA Jornada Experimental Range (Jornada) in NM. Major minerals observed at Alfalfa and Jornada are calcite, quartz, and feldspars. Calcite/quartz ratios increase upward in the profile at Alfalfa, suggesting formation of carbonates in shallow soils. Consistently, total carbon increases toward the soil surface at Alfalfa, contributed by both soil organic carbon and soil inorganic carbon (pedogenic carbonates). Concentrations of major elements (e.g Ca, Mg, and Sr) also increase toward the surface at Alfalfa, suggesting surface addition. Alternating trends of enrichment and depletion are observed throughout the soil profiles. In contrast, calcite/quartz ratios decrease toward the surface at Jornada, indicative of leaching at shallow soils and redeposition of calcite at depth. This is in agreement with high soil inorganic carbon contents measured at depth. At Jornada however, the Ca, Mg and Sr concentrations decrease toward the surface, showing typical depletion profiles. (234U/238U) activity ratios in bulk soils increase upward at Alfalfa while at Jornada (234U/238U) ratios decrease toward the surface. (234U/238U) ratios at Alfalfa suggest surface addition of U onto shallow soils probably from irrigation water, which is known to have high (234U/238U) ratios. Jornada shows preferential loss of 234U upward. U-series disequilibrium in pedogenic carbonates enables calculation of their formation ages. At Alfalfa, carbonate ages range from 2

  12. Trapped mountain wave excitations over the Kathmandu valley, Nepal

    NASA Astrophysics Data System (ADS)

    Regmi, Ram P.; Maharjan, Sangeeta

    2015-11-01

    Mid-wintertime spatial and temporal distributions of mountain wave excitation over the Kathmandu valley has been numerically simulated using Weather Research and Forecasting (WRF) modeling system. The study shows that low-level trapped mountain waves may remain very active during the night and early morning in the sky over the southern rim of the surrounding mountains, particularly, over the lee of Mt. Fulchoki. Calculations suggest that mountain wave activities are at minimum level during afternoon. The low-level trapped mountain waves in the sky over southern gateway of Tribhuvan International Airport (TIA) may pose risk for landings and takeoffs of light aircrafts. Detailed numerical and observational studies would be very important to reduce risk of air accidents and discomfort in and around the Kathmandu valley.

  13. Ground Watering of the Death Valley Region, Nevada and California

    SciTech Connect

    USGS

    2006-10-12

    Water is a precious commodity, especially in the arid southwest region of the US, where there is a limited supply of both surface water and ground water. Ground water has a variety of uses (such as agricultural, commercial, and domestic) in the Death Valley regional ground-water flow system (DVRFS) of southern Nevada and eastern California. The DVRFS, an area of about 100,000 square kilometers, contains very complex geology and hydrology. Using a computer model to represent this complex system the US Geological Survey (USGS) simulated ground-water flow in the Death Valley region for use with US Department of Energy (DOE) projects in southern Nevada. The model was created to help address contaminant cleanup activities associated with the underground nuclear testing conducted from 1951 to 1992 at the Nevada Test Site and to support the licensing process for the Nation's proposed geologic repository for high-level nuclear waste at Yucca Mountain, Nevada.

  14. Hydrogeologic Framework and Ground Water in Basin-Fill Deposits of the Diamond Valley Flow System, Central Nevada

    USGS Publications Warehouse

    Tumbusch, Mary L.; Plume, Russell W.

    2006-01-01

    The Diamond Valley flow system, an area of about 3,120 square miles in central Nevada, consists of five hydrographic areas: Monitor, Antelope, Kobeh, and Diamond Valleys and Stevens Basin. Although these five areas are in a remote part of Nevada, local government officials and citizens are concerned that the water resources of the flow system eventually could be further developed for irrigation or mining purposes or potentially for municipal use outside the study area. In order to better understand the flow system, the U.S. Geological Survey in cooperation with Eureka, Lander, and Nye Counties and the Nevada Division of Water Resources, is conducting a multi-phase study of the flow system. The principal aquifers of the Diamond Valley flow system are in basin-fill deposits that occupy structural basins comprised of carbonate rocks, siliciclastic sedimentary rocks, igneous intrusive rocks, and volcanic rocks. Carbonate rocks also function as aquifers, but their extent and interconnections with basin-fill aquifers are poorly understood. Ground-water flow in southern Monitor Valley is from the valley margins toward the valley axis and then northward to a large area of discharge by evapotranspiration (ET) that is formed south of a group of unnamed hills near the center of the valley. Ground-water flow from northern Monitor Valley, Antelope Valley, and northern and western parts of Kobeh Valley converges to an area of ground-water discharge by ET in central and eastern Kobeh Valley. Prior to irrigation development in the 1960s, ground-water flow in Diamond Valley was from valley margins toward the valley axis and then northward to a large discharge area at the north end of the valley. Stevens Basin is a small upland basin with internal drainage and is not connected with other parts of the flow system. After 40 years of irrigation pumping, a large area of ground-water decline has developed in southern Diamond Valley around the irrigated area. In this part of Diamond

  15. Morphological analysis and evolution of buried tunnel valleys in northeast Alberta, Canada

    NASA Astrophysics Data System (ADS)

    Atkinson, N.; Andriashek, L. D.; Slattery, S. R.

    2013-04-01

    Tunnel valleys are large elongated depressions eroded into unconsolidated sediments and bedrock. Tunnel valleys are believed to have been efficient drainage pathways for large volumes of subglacial meltwater, and reflect the interplay between groundwater flow and variations in the hydraulic conductivity of the substrate, and basal meltwater production and associated water pressure variations at the ice-bed interface. Tunnel valleys are therefore an important component of the subglacial hydrological system. Three-dimensional modelling of geophysical and lithological data has revealed numerous buried valleys eroded into the bedrock unconformity in northeast Alberta, many of which are interpreted to be tunnel valleys. Due to the very high data density used in this modelling, the morphology, orientation and internal architecture of several of these tunnel valleys have been determined. The northeast Alberta buried tunnel valleys are similar to the open tunnel valleys described along the former margins of the southern Laurentide Ice Sheet. They have high depth to width ratios, with undulating, low gradient longitudinal profiles. Many valleys start and end abruptly, and occur as solitary, straight to slightly sinuous incisions, or form widespread anastomosing networks. Typically, these valleys are between 0.5 and 3 km wide and 10 and 30 m deep, although the depth of incision along some thalwegs exceeds 100 m. Several valleys extend for up to 60 km, but most are between 10 and 30 km long. Valley fills comprise a range of lithofacies, including stacked sequences of diamict, glaciofluvial sands and gravels and glaciolacustrine silts and clays. Displaced bedrock, presumably of glaciotectonic origin, also occurs within several anastomosing valleys. Several channel bodies are exposed along a number of valley sections suggesting progressive valley development through repeated cycles of sediment discharge. Cut-and-fill structures that are capped by fine-grained sequences of

  16. An Ancient Valley Network

    NASA Image and Video Library

    2017-05-09

    Most of the oldest terrains on Mars have eroded into branching valleys, as seen here in by NASA's Mars Reconnaisance Orbiter, much like many land regions of Earth are eroded by rain and snowmelt runoff. This is the primary evidence for major climate change on Mars billions of years ago. How the climate of Mars could have supported a warmer and wetter environment has been the subject of scientific debates for 40 years. A full-resolution enhanced color closeup reveals details in the bedrock and dunes on the valley floor (upper left). The bedrock of ancient Mars has been hardened and cemented by groundwater. https://photojournal.jpl.nasa.gov/catalog/PIA21630

  17. [Neurologic and neurosensory forms of Rift Valley fever in Mauritania].

    PubMed

    Riou, O; Philippe, B; Jouan, A; Coulibaly, I; Mondo, M; Digoutte, J P

    1989-01-01

    During and after a Rift Valley fever epidemic in Southern Mauritania, we observed 348 patients infected by RVF virus. 17 of them had encephalitis. These belonged to 2 groups, acute febrile forms with short duration and possibility of death, and sub-acute forms, with a longer duration and with sequelae. They were pure encephalitis, without clinical or biological meningeal signs. We also noticed 5 brutal ocular attacks, running very slowly, with sequelae.

  18. [Rift valley fever].

    PubMed

    Markin, V A; Pantiukhov, V B; Markov, V I; Bondarev, V P

    2012-01-01

    In the last quarter of century virus of Rift valley fever (RVF) sharply extended its distribution by moving from Africa to Asia and evolving from low- to high pathogenic for humans causing severe hemorrhagic disease, practically equaling in this respect with some members ofa group of extremely dangerous pathogens. Morbidity and epidemics of RVF are analyzed. Evolution of epidemic development of the infection is examined. Necessity of development of means and methods for diagnostics, prophylaxis and therapy of RVF is underlined.

  19. Crustal formation and evolution processes in the Natal Valley and Mozambique Ridge, off South Africa

    NASA Astrophysics Data System (ADS)

    Hanyu, Tomoko; Nogi, Yoshifumi; Fujii, Masakazu

    2017-09-01

    The evolution of seafloor spreading of Africa, South America, and Antarctica is key to understanding the initial break-up of Gondwana. Vector geomagnetic surveys were conducted in the Natal Valley and Mozambique Ridge, off South Africa. We summarize the nature of the crust using the results of dense vector geomagnetic anomaly data, as well as satellite gravity data. Based on both inversion and forward analytical results, we identified areas of stretched continental crust, with basaltic magma intrusion in parts, as the northern Natal Valley, north part of the Mozambique Ridge, and north part of the southern Natal Valley. Oceanic crust was identified in the south part of the southern Natal Valley and south part of the Mozambique Ridge. Magnetic isochrons M0-M10 were identified in the south part of the southern Natal Valley. Clear magnetic lineations were observed in the south part of the Mozambique Ridge, where some areas were distorted by hotspot volcanism. The location of the continental ocean boundary in the Natal Valley, along with a four-stage model of tectonic evolution of the study area since about 183 Ma, are newly proposed.

  20. Influence of elevation and forest type on community assemblage and species distribution of shrews in the central and southern Appalachian mountains

    Treesearch

    W. Mark Ford; Timothy S. McCay; Michael A. Menzel; W. David Webster; Cathryn H. Greenberg; John F. Pagels; Joseph F. Merritt; Joseph F. Merritt

    2005-01-01

    We analyzed shrew community data from 398,832 pitfall trapnights at 303 sites across the upper Piedmont, Blue Ridge, northern Ridge and Valley, southern Ridge and Valley, Cumberland Plateau and Allegheny Mountains and Plateau sections of the central and southern Appalachian Mountains from Alabama to Pennsylvania. The objectives of our research were to describe regional...

  1. Influence of elevation and forest type on community assemblage and species distribution of shrews in the central and southern Appalachian mountains

    Treesearch

    W. Mark Ford; Timothy S. McCay; Michael A. Menzel; W. David Webster; Cathryn H. Greenberg; John F. Pagels; Joseph F. Merritt

    2005-01-01

    We analyzed shrew community data from 398,832 pitfall trapnights at 303 sites across the upper Piedmont, Blue ridge, northern Ridge and Valley, southern Ride and Valley, Cumberland Plateau and Allegheny Mountains and Plateau sections of the central and southern Appalachian Mountains from Alabama to Pennsylvania. The objectives of our research were to describe regional...

  2. Influence of elevation and forest type on community assemblage and species distribution of shrews in the central and southern Appalachian Mountains

    Treesearch

    W. Mark Ford; Timothy S. McCay; Michael A. Menzel; W. David Webster; Cathryn H. Greenberg; John F. Pagels; Joseph F. Merritt

    2006-01-01

    We analyzed shrew community data from 398,832 pitfall trapnights at 303 sites across the upper Piedmont, Blue Ridge, northern Ridge and Valley, southern Ridge and Valley, Cumberland Plateau and Allegheny Mountains and Plateau sections of the central and southern Appalachian Mountains from Alabama to Pennsylvania. The objectives of our research were to describe regional...

  3. Water-level changes (1975-1998) in the Antelope Valley ground-water basin, California

    USGS Publications Warehouse

    Carlson, Carl S.; Phillips, Steven P.

    1998-01-01

    Antelope Valley is in the western part of the Mojave Desert in southern California, about 50 mi northeast of Los Angeles. Between 1975 and 1998, water levels in the valley have changed in response to a shift in ground-water use from agricultural to urban, declining in some areas and rising in others. A study to document these changes was conducted by the U.S. Geological Survey in cooperation with the Antelope Valley Water Group. This report presents the water-level data and the changes that occurred during this study period.

  4. Fluvial valleys and Martian palaeoclimates

    NASA Astrophysics Data System (ADS)

    Gulick, Virginia C.; Baker, Victor R.

    1989-10-01

    Theoretical models of early Martian atmospheric evolution describe the maintenance of a dense CO2 atmosphere and a warm, wet climate until the end of the heavy-bombardment phase of impacting. However, the presence of very young, earthlike fluvial valleys on the northern flank of Alba Patera conflicts with this scenario. Whereas the widespread ancient Martian valleys generally have morphologies indicative of sapping erosion by the slow outflow of subsurface water, the local Alba valleys were probably formed by surface-runoff processes. Because subsurface water flow might be maintained by hydrothermal energy inputs and because surface-runoff valleys developed late in Martian history, it is not necessary to invoke drastically different planet-wide climatic conditions to explain valley development on Mars. The Alba fluvial valleys can be explained by hydrothermal activity or outflow-channel discharges that locally modified the atmosphere, including precipitation and local overland flow on low-permeability volcanic ash.

  5. Mars Rover Opportunity Panorama of Marathon Valley (Enhanced Color)

    NASA Image and Video Library

    2016-06-14

    "Marathon Valley" on Mars opens northeastward to a view across the floor of Endeavour Crater in this scene from the panoramic camera (Pancam) of NASA's Mars Exploration Rover Opportunity. In this version of the scene the landscape is presented in enhanced color to make differences in surface materials more easily visible. The panorama merges multiple Pancam exposures taken during the period April 16 through May 15, 2016, corresponding to sols (Martian days) 4,347 through 4,375 of Opportunity's work on Mars. It spans from north, at the left, to west-southwest, at the right. The high point in the right half of the scene is "Knudsen Ridge," which forms part of the southern edge of Marathon Valley. Portions of the northeastern and eastern rim of Endeavour crater appear on the distant horizon. Endeavour Crater is 14 miles (22 kilometers) in diameter. The fractured texture of Marathon Valley's floor is visible in the foreground. The rover team calls this image the mission's "Sacagawea Panorama," for the Lemhi Shoshone woman, also commemorated on U.S. dollar coins, whose assistance to the Lewis and Clark expedition helped enable its successes in 1804-1806. Many rocks and other features in Marathon Valley were informally named for members of Lewis and Clark's "Corps of Discovery" expedition. Opportunity entered Marathon Valley in July 2015. The valley's informal name was chosen because Opportunity's arrival at this point along the western rim of Endeavour Crater coincided closely with the rover surpassing marathon-footrace distance in its total driving odometry since landing on Mars in January 2004. The team's planned investigations in the valley were nearing completion when the component images for this scene were taken. http://photojournal.jpl.nasa.gov/catalog/PIA20750

  6. Mars Rover Opportunity Panorama of Marathon Valley Stereo

    NASA Image and Video Library

    2016-06-14

    "Marathon Valley" on Mars opens northeastward in this stereo scene from the panoramic camera (Pancam) of NASA's Mars Exploration Rover Opportunity. The image combines views from the left eye and right eye of the Pancam to appear three-dimensional when seen through blue-red glasses with the red lens on the left. The component images were taken during the period April 16 through May 15, 2016, corresponding to sols (Martian days) 4,347 through 4,375 of Opportunity's work on Mars. The vista spans from north, at the left, to west-southwest, at the right. The high point in the right half of the scene is "Knudsen Ridge," which forms part of the southern edge of Marathon Valley. The fractured texture of Marathon Valley's floor is visible in the foreground. The rover team calls this image the mission's "Sacagawea Panorama," for the Lemhi Shoshone woman, also commemorated on U.S. dollar coins, whose assistance to the Lewis and Clark expedition helped enable its successes in 1804-1806. Many rocks and other features in Marathon Valley were informally named for members of Lewis and Clark's "Corps of Discovery" expedition. Opportunity entered Marathon Valley in July 2015. The valley's informal name was chosen because Opportunity's arrival at this point along the western rim of Endeavour Crater coincided closely with the rover surpassing marathon-footrace distance in its total driving odometry since landing on Mars in January 2004. The team's planned investigations in the valley were nearing completion when the component images for this scene were taken. http://photojournal.jpl.nasa.gov/catalog/PIA20751

  7. Groundwater quality in the Southern Sierra Nevada, California

    USGS Publications Warehouse

    Fram, Miranda S.; Belitz, Kenneth

    2012-01-01

    Groundwater provides more than 40 percent of California's drinking water. To protect this vital resource, the State of California created the Groundwater Ambient Monitoring and Assessment (GAMA) Program. The Priority Basin Project of the GAMA Program provides a comprehensive assessment of the State's groundwater quality and increases public access to groundwater-quality information. The Tehachapi-Cummings Valley and Kern River Valley basins and surrounding watersheds in the Southern Sierra Nevada constitute one of the study units being evaluated.

  8. Signatures in Lightning Activity during Tennessee Valley Severe Storms of 5-6 May 2003

    NASA Technical Reports Server (NTRS)

    Gatlin, Patrick N.; Goodman, Steven J.

    2004-01-01

    During the first week of May 2003, the Tennessee Valley experienced 14 tornadoes. Those that moved across the Tennessee Valley Region of northern Alabama and southern Tennessee provided an opportunity for study us- ing the North Alabama Lightning Mapping Array (LMA). On 5 May a classic supercell trekked across southern Tennessee spawning several tornadoes producing FO-F3 damage; on 6 May a high precipitation supercell moved across northern Alabama producing several FO-F1 tornadoes. The life cycle of these supercells will be discussed by presenting their electrical and radar evolution.

  9. Outlook for Appalachian-Cumberland forests: a subregional report from the Southern Forest Futures Project

    Treesearch

    Tara Keyser; Joy Malone; Claudia Cotton; Jeffrey Lewis

    2014-01-01

    The U.S. Appalachian-Cumberland highland consists of about 62.3 million acres in portions of Alabama, Georgia, North Carolina, Tennessee, Kentucky, and Virginia; and is divided into five sections - Blue Ridge Mountains; Interior Low Plateau; Northern Ridge and Valley; Southern Ridge and Valley; and Cumberland Plateau and Mountains. Appalachian-Cumberland forests...

  10. Optical manipulation of valley pseudospin

    SciTech Connect

    Ye, Ziliang; Sun, Dezheng; Heinz, Tony F.

    2016-09-19

    The coherent manipulation of spin and pseudospin underlies existing and emerging quantum technologies, including quantum communication and quantum computation. Valley polarization, associated with the occupancy of degenerate, but quantum mechanically distinct valleys in momentum space, closely resembles spin polarization and has been proposed as a pseudospin carrier for the future quantum electronics. Valley exciton polarization has been created in the transition metal dichalcogenide monolayers using excitation by circularly polarized light and has been detected both optically and electrically. In addition, the existence of coherence in the valley pseudospin has been identified experimentally. The manipulation of such valley coherence has, however, remained out of reach. In this paper, we demonstrate all-optical control of the valley coherence by means of the pseudomagnetic field associated with the optical Stark effect. Using below-bandgap circularly polarized light, we rotate the valley exciton pseudospin in monolayer WSe2 on the femtosecond timescale. Both the direction and speed of the rotation can be manipulated optically by tuning the dynamic phase of excitons in opposite valleys. Finally, this study unveils the possibility of generation, manipulation, and detection of the valley pseudospin by coupling to photons.

  11. Optical manipulation of valley pseudospin

    DOE PAGES

    Ye, Ziliang; Sun, Dezheng; Heinz, Tony F.

    2016-09-19

    The coherent manipulation of spin and pseudospin underlies existing and emerging quantum technologies, including quantum communication and quantum computation. Valley polarization, associated with the occupancy of degenerate, but quantum mechanically distinct valleys in momentum space, closely resembles spin polarization and has been proposed as a pseudospin carrier for the future quantum electronics. Valley exciton polarization has been created in the transition metal dichalcogenide monolayers using excitation by circularly polarized light and has been detected both optically and electrically. In addition, the existence of coherence in the valley pseudospin has been identified experimentally. The manipulation of such valley coherence has, however,more » remained out of reach. In this paper, we demonstrate all-optical control of the valley coherence by means of the pseudomagnetic field associated with the optical Stark effect. Using below-bandgap circularly polarized light, we rotate the valley exciton pseudospin in monolayer WSe2 on the femtosecond timescale. Both the direction and speed of the rotation can be manipulated optically by tuning the dynamic phase of excitons in opposite valleys. Finally, this study unveils the possibility of generation, manipulation, and detection of the valley pseudospin by coupling to photons.« less

  12. Optical manipulation of valley pseudospin

    NASA Astrophysics Data System (ADS)

    Ye, Ziliang; Sun, Dezheng; Heinz, Tony F.

    2017-01-01

    The coherent manipulation of spin and pseudospin underlies existing and emerging quantum technologies, including quantum communication and quantum computation. Valley polarization, associated with the occupancy of degenerate, but quantum mechanically distinct valleys in momentum space, closely resembles spin polarization and has been proposed as a pseudospin carrier for the future quantum electronics. Valley exciton polarization has been created in the transition metal dichalcogenide monolayers using excitation by circularly polarized light and has been detected both optically and electrically. In addition, the existence of coherence in the valley pseudospin has been identified experimentally. The manipulation of such valley coherence has, however, remained out of reach. Here we demonstrate all-optical control of the valley coherence by means of the pseudomagnetic field associated with the optical Stark effect. Using below-bandgap circularly polarized light, we rotate the valley exciton pseudospin in monolayer WSe2 on the femtosecond timescale. Both the direction and speed of the rotation can be manipulated optically by tuning the dynamic phase of excitons in opposite valleys. This study unveils the possibility of generation, manipulation, and detection of the valley pseudospin by coupling to photons.

  13. Southern California as seen from the Apollo 7 spacecraft

    NASA Image and Video Library

    1968-10-12

    This view of southern California as seen from the Apollo 7 spacecraft during its 18th revolution of the earth. Photographed from an altitude of 124 nautical miles. The coast of California can be seen from Point Mugu southward to Oceanside. Santa Catalina can be seen below the off shore clouds. Details of the Los Angeles area are obscured by pollution which extends from Banning westard for 100 miles to beyond Malibu. In the upper portion of the photograph can be seen (left to right) the San Joaquin Valley beyond Bakersfield, the Techachapi Mountains, the Sierra Nevada, Owens Valley, Death Valley and the Mojave Desert.

  14. Southern California as seen from the Apollo 7 spacecraft

    NASA Technical Reports Server (NTRS)

    1968-01-01

    This view of southern California as seen from the Apollo 7 spacecraft during its 18th revolution of the earth. Photographed from an altitude of 124 nautical miles. The coast of California can be seen from Point Mugu southward to Oceanside. Santa Catalina can be seen below the off shore clouds. Details of the Los Angeles area are obscured by pollution which extends from Banning westard for 100 miles to beyond Malibu. In the upper portion of the photograph can be seen (left to right) the San Joaquin Valley beyond Bakersfield, the Techachapi Mountains, the Sierra Nevada, Owens Valley, Death Valley and the Mojave Desert.

  15. Death Valley, California

    NASA Image and Video Library

    1994-04-11

    STS059-S-026 (11 April 1994) --- This is an image of Death Valley, California, centered at 36.629 degrees north latitude, 117.069 degrees west longitude. The image shows Furnace Creek alluvial fan and Furnace Creek Ranch at the far right, and the sand dunes near Stove Pipe Wells at the center. The dark fork-shaped feature between Furnace Creek fan and the dunes is a smooth flood-plain which encloses Cottonball Basin. The SIR-C/X-SAR supersite is an area of extensive field investigations and has been visited by both Space Radar Lab astronaut crews. Elevations in the Valley range from 70 meters below sea level, the lowest in the United States, to more than 3300 meters above sea level. Scientists are using SIR-C/X-SAR data from Death Valley to help answer a number of different questions about the Earth's geology. One question concerns how alluvial fans are formed and change through time under the influence of climatic changes and earthquakes. Alluvial fans are gravel deposits that wash down from the mountains over time. They are visible in the image as circular, fan-shaped bright areas extending into the darker valley floor from the mountains. Information about the alluvial fans help scientists study Earth's ancient climate. Scientists know the fans are bulit up through climatic and tectonic processes and they will use the SIR-C/X-SAR data to understand the nature and rates of weathering processes on the fans, soil formation, and the transport of sand and dust by the wind. SIR-C/X-SAR's sensitivity to centimeter-scale (or inch-scale) roughness provides detailed maps of surface texture. Such information can be used to study the occurrence and movement of dust storms and sand dunes. the goal of these studies is to gain a better understanding of the record of past climatic changes and the effects of those changes on a sensitive environment. This may lead to a better ability to predict future response of the land to different potential global cimate-change scenarios

  16. The California Valley grassland

    USGS Publications Warehouse

    Keeley, J.E.; Schoenherr, Allan A.

    1990-01-01

    Grasslands are distributed throughout California from Oregon to Baja California Norte and from the coast to the desert (Brown 1982) (Figure 1). This review will focus on the dominant formation in cismontane California, a community referred to as Valley Grassland (Munz 1959). Today, Valley Grassland is dominated by non-native annual grasses in genera such as Avena (wild oat), Bromus (brome grass), and Hordeum (barley), and is often referred to as the California annual grassland. On localized sites, native perennial bunchgrasses such as Stipa pultra (purple needle grass) may dominate and such sites are interpreted to be remnants of the pristine valley grassland. In northwestern California a floristically distinct formation of the Valley Grassland, known as Coast Prairie (Munz 1959) or Northern Coastal Grassland (Holland and Keil 1989) is recognized. The dominant grasses include many native perennial bunchgrasses in genera such as Agrostis, Calamagrostis, Danthonia, Deschampsia, Festuca, Koeleria and Poa (Heady et al. 1977). Non-native annuals do not dominate, but on some sites non-native perennials like Anthoxanthum odoratum may colonize the native grassland (Foin and Hektner 1986). Elevationally, California's grasslands extend from sea level to at leas 1500 m. The upper boundary is vague because montane grassland formations are commonly referred to as meadows; a community which Munz (1959) does not recognize. Holland and Keil (1989) describe the montane meadow as an azonal community; that is, a community restricted not so much to a particular climatic zone but rather controlled by substrate characteristics. They consider poor soil-drainage an over-riding factor in the development of montane meadows and, in contrast to grasslands, meadows often remain green through the summer drought. Floristically, meadows are composed of graminoids; Cyperaceae, Juncaceae, and rhizomatous grasses such as Agropyron (wheat grass). Some bunchgrasses, such as Muhlenbergia rigens, are

  17. Flow Along Valley Floors

    NASA Technical Reports Server (NTRS)

    2003-01-01

    [figure removed for brevity, see original site]

    Released 9 May 2003

    Lines indicative of flow in a valley floor (east to west) cut across similar lines in a slightly smaller valley (southeast to northwest), indicating both that material flowed along the valley floor (as opposed to across it) and that relative flow ages may be determined from crosscutting relationships.

    Image information: VIS instrument. Latitude 39.6, Longitude 31.1East (328.9). 19 meter/pixel resolution.

    Note: this THEMIS visual image has not been radiometrically nor geometrically calibrated for this preliminary release. An empirical correction has been performed to remove instrumental effects. A linear shift has been applied in the cross-track and down-track direction to approximate spacecraft and planetary motion. Fully calibrated and geometrically projected images will be released through the Planetary Data System in accordance with Project policies at a later time.

    NASA's Jet Propulsion Laboratory manages the 2001 Mars Odyssey mission for NASA's Office of Space Science, Washington, D.C. The Thermal Emission Imaging System (THEMIS) was developed by Arizona State University, Tempe, in collaboration with Raytheon Santa Barbara Remote Sensing. The THEMIS investigation is led by Dr. Philip Christensen at Arizona State University. Lockheed Martin Astronautics, Denver, is the prime contractor for the Odyssey project, and developed and built the orbiter. Mission operations are conducted jointly from Lockheed Martin and from JPL, a division of the California Institute of Technology in Pasadena.

  18. Synthetic River Valleys

    NASA Astrophysics Data System (ADS)

    Brown, R.; Pasternack, G. B.

    2011-12-01

    The description of fluvial form has evolved from anecdotal descriptions to artistic renderings to 2D plots of cross section or longitudinal profiles and more recently 3D digital models. Synthetic river valleys, artificial 3D topographic models of river topography, have a plethora of potential applications in fluvial geomorphology, and the earth sciences in general, as well as in computer science and ecology. Synthetic river channels have existed implicitly since approximately the 1970s and can be simulated from a variety of approaches spanning the artistic and numerical. An objective method of synthesizing 3D stream topography based on reach scale attributes would be valuable for sizing 3D flumes in the physical and numerical realms, as initial input topography for morphodynamic models, stream restoration design, historical reconstruction, and mechanistic testing of interactions of channel geometric elements. Quite simply - simulation of synthetic channel geometry of prescribed conditions can allow systematic evaluation of the dominant relationships between river flow and geometry. A new model, the control curve method, is presented that uses hierarchically scaled parametric curves in over-lapping 2D planes to create synthetic river valleys. The approach is able to simulate 3D stream geometry from paired 2D descriptions and can allow experimental insight into form-process relationships in addition to visualizing past measurements of channel form that are limited to two dimension descriptions. Results are presented that illustrate the models ability to simulate fluvial topography representative of real world rivers as well as how channel geometric elements can be adjusted. The testing of synthetic river valleys would open up a wealth of knowledge as to why some 3D attributes of river channels are more prevalent than others as well as bridging the gap between the 2D descriptions that have dominated fluvial geomorphology the past century and modern, more complete, 3D

  19. Valley Glaciers on Pluto

    NASA Image and Video Library

    2015-09-17

    Ice (probably frozen nitrogen) that appears to have accumulated on the uplands on the right side of this 390-mile (630-kilometer) wide image is draining from Pluto's mountains onto the informally named Sputnik Planum through the 2- to 5-mile (3- to 8- kilometer) wide valleys. The flow front of the ice moving into Sputnik Planum is outlined by the blue arrows. The origin of the ridges and pits on the right side of the image remains uncertain. http://photojournal.jpl.nasa.gov/catalog/PIA19944

  20. Southern Pinwheel

    NASA Image and Video Library

    2010-06-28

    This image from NASA Wide-field Infrared Survey Explorer shows the nearby galaxy M83. This is a spiral galaxy approximately 15 million light-years away in the constellation Hydra, sometimes referred to as the southern Pinwheel galaxy.

  1. Land use in the northern Coachella Valley

    NASA Technical Reports Server (NTRS)

    Bale, J. B.; Bowden, L. W.

    1973-01-01

    Satellite imagery has proved to have great utility for monitoring land use change and as a data source for regional planning. In California, open space desert resources are under severe pressure to serve as a source for recreational gratification to individuals living in the heavily populated southern coastal plain. Concern for these sensitive arid environments has been expressed by both federal and state agencies. The northern half of the Coachella Valley has historically served as a focal point for weekend recreational activity and second homes. Since demand in this area has remained high, land use change from rural to urban residential has been occurring continuously since 1968. This area of rapid change is an ideal site to illustrate the utility of satellite imagery as a data source for planning information, and has served as the areal focus of this investigation.

  2. Addendum to sources of powerplant cooling water in the desert area of Southern California: a reconnaissance study

    USGS Publications Warehouse

    Koehler, J.H.; Mallory, Michael J.

    1981-01-01

    A hydrologic reconnaissance study was made in five basins in southern California previously classified as suitable for providing sufficient ground water for cooling a 1,000-megawatt electric-power generating plant. The criteria used to evaluate the basins were (1) theoretical aquifer response to pumping, (2) alternative sources of water, and (3) chemical quality of water. The basins were ranked relative to each other for the three criteria and in overall suitability. On the basis of subjective analysis, the basins were ranked in the following order for overall suitability: (1) Calzona-Vidal Valley, (2) Middle Amargosa Valley, (3) Chuckwalla Valley, (4) Soda Lake Valley, and (5) Caves Canyon Valley. (USGS)

  3. Global Positioning System measurements of strain accumulation across the Imperial Valley, California - 1986-1989

    NASA Technical Reports Server (NTRS)

    Larsen, Shawn; Reilinger, Robert

    1992-01-01

    The Global Positioning System (GPS) data collected in southern California from 1986 to 1989 indicate considerable strain accumulation across the Imperial Valley. Displacements are computed at 29 stations in and near the valley from 1986 to 1988, and at 11 sites from 1988 to 1989. The earlier measurements indicate 5.9 =/- 1.0 cm/yr right-lateral differential velocity across the valley, although the data are heavily influenced by the 1987 Superstition Hills earthquake sequence. Some measurements, especially the east-trending displacements, are suspects for large errors. The 1988 to 1989 GPS displacements are best modeled by 5.2 =/- 0.9 cm/yr of valley crossing deformation, but rates calculated from conventional geodetic measurements (3.4 to 4.3 cm/yr) fit the data nearly as well. There is evidence from GPS and Very Long Base Interferometry (VLBI) observations that the present slip rate along the southern San Andreas fault is smaller than the long-term geologic estimate, suggesting a lower earthquake potential than is currently assumed. Correspondingly, a higher earthquake potential is indicated for the San Jacinto fault. The Imperial Valley GPS sites form part of a 183 station network in southern California and northern Baja California, which spans a cross-section of the North American-Pacific plate boundary.

  4. GPS measurements of strain accumulation across the Imperial Valley, California: 1986-1989

    NASA Technical Reports Server (NTRS)

    Larsen, Shawn; Reilinger, Robert

    1989-01-01

    The Global Positioning System (GPS) data collected in southern California from 1986 to 1989 indicate considerable strain accumulation across the Imperial Valley. Displacements are computed at 29 stations in and near the valley from 1986 to 1988, and at 11 sites from 1988 to 1989. The earlier measurements indicate 5.9 +/- 1.0 cm/yr right-lateral differential velocity across the valley, although the data are heavily influenced by the 1987 Superstition Hills earthquake sequence. Some measurements, especially the east-trending displacements, are suspects for large errors. The 1988 to 1989 GPS displacements are best modeled by 5.2 +/- 0.9 cm/yr of valley crossing deformation, but rates calculated from conventional geodetic measurements (3.4 to 4.3 cm/yr) fit the data nearly as well. There is evidence from GPS and Very Long Base Interferometry (VLBI) observations that the present slip rate along the southern San Andreas fault is smaller than the long-term geologic estimate, suggesting a lower earthquake potential than is currently assumed. Correspondingly, a higher earthquake potential is indicated for the San Jacinto fault. The Imperial Valley GPS sites form part of a 183 station network in southern California and northern Baja California, which spans a cross-section of the North American-Pacific plate boundary.

  5. Global Positioning System measurements of strain accumulation across the Imperial Valley, California - 1986-1989

    NASA Technical Reports Server (NTRS)

    Larsen, Shawn; Reilinger, Robert

    1992-01-01

    The Global Positioning System (GPS) data collected in southern California from 1986 to 1989 indicate considerable strain accumulation across the Imperial Valley. Displacements are computed at 29 stations in and near the valley from 1986 to 1988, and at 11 sites from 1988 to 1989. The earlier measurements indicate 5.9 =/- 1.0 cm/yr right-lateral differential velocity across the valley, although the data are heavily influenced by the 1987 Superstition Hills earthquake sequence. Some measurements, especially the east-trending displacements, are suspects for large errors. The 1988 to 1989 GPS displacements are best modeled by 5.2 =/- 0.9 cm/yr of valley crossing deformation, but rates calculated from conventional geodetic measurements (3.4 to 4.3 cm/yr) fit the data nearly as well. There is evidence from GPS and Very Long Base Interferometry (VLBI) observations that the present slip rate along the southern San Andreas fault is smaller than the long-term geologic estimate, suggesting a lower earthquake potential than is currently assumed. Correspondingly, a higher earthquake potential is indicated for the San Jacinto fault. The Imperial Valley GPS sites form part of a 183 station network in southern California and northern Baja California, which spans a cross-section of the North American-Pacific plate boundary.

  6. Global Positioning System measurements of strain accumulation across the Imperial Valley, California - 1986-1989

    NASA Astrophysics Data System (ADS)

    Larsen, Shawn; Reilinger, Robert

    1992-06-01

    The Global Positioning System (GPS) data collected in southern California from 1986 to 1989 indicate considerable strain accumulation across the Imperial Valley. Displacements are computed at 29 stations in and near the valley from 1986 to 1988, and at 11 sites from 1988 to 1989. The earlier measurements indicate 5.9 =/- 1.0 cm/yr right-lateral differential velocity across the valley, although the data are heavily influenced by the 1987 Superstition Hills earthquake sequence. Some measurements, especially the east-trending displacements, are suspects for large errors. The 1988 to 1989 GPS displacements are best modeled by 5.2 =/- 0.9 cm/yr of valley crossing deformation, but rates calculated from conventional geodetic measurements (3.4 to 4.3 cm/yr) fit the data nearly as well. There is evidence from GPS and Very Long Base Interferometry (VLBI) observations that the present slip rate along the southern San Andreas fault is smaller than the long-term geologic estimate, suggesting a lower earthquake potential than is currently assumed. Correspondingly, a higher earthquake potential is indicated for the San Jacinto fault. The Imperial Valley GPS sites form part of a 183 station network in southern California and northern Baja California, which spans a cross-section of the North American-Pacific plate boundary.

  7. Data network, collection, and analysis in the Diamond Valley flow system, central Nevada

    USGS Publications Warehouse

    Knochenmus, Lari A.; Berger, David L.; Moreo, Michael T.; Smith, J. LaRue

    2011-01-01

    Future groundwater development and its effect on future municipal, irrigation, and alternative energy uses in the Diamond Valley flow system are of concern for officials in Eureka County, Nevada. To provide a better understanding of the groundwater resources, the U.S. Geological Survey, in cooperation with Eureka County, commenced a multi-phase study of the Diamond Valley flow system in 2005. Groundwater development primarily in southern Diamond Valley has resulted in water-level declines since the 1960s ranging from less than 5 to 100 feet. Groundwater resources in the Diamond Valley flow system outside of southern Diamond Valley have been relatively undeveloped. Data collected during phase 2 of the study (2006-09) included micrometeorological data at 4 evapotranspiration stations, 3 located in natural vegetation and 1 located in an agricultural field; groundwater levels in 95 wells; water-quality constituents in aquifers and springs at 21 locations; lithologic information from 7 recently drilled wells; and geophysical logs from 3 well sites. This report describes what was accomplished during phase 2 of the study, provides the data collected, and presents the approaches to strengthen relations between evapotranspiration rates measured at micrometeorological stations and spatially distributed groundwater discharge. This report also presents the approach to improve delineation of areas of groundwater discharge and describes the current methodology used to improve the accuracy of spatially distributed groundwater discharge rates in the Diamond Valley flow system.

  8. Coachella Valley, CA

    NASA Technical Reports Server (NTRS)

    2001-01-01

    These band composites, acquired on June 4, 2000, cover a 11 by 13.5 km sub-scene in the Coachella Valley, CA. The area is shown by the yellow box on the full scene in the LOWER RIGHT corner, northwest of the Salton Sea. This is a major agricultural region of California, growing fruit and produce throughout the year. Different combinations of ASTER bands help identify the different crop types. UPPER LEFT: bands 3, 2, 1 as red, green, and blue (RGB); UPPER RIGHT: bands 4, 2, 1 as RGB; LOWER LEFT: bands 4, 3, 2 as RGB. The image is centered at 33.6 degrees north latitude, 116.1 degrees west longitude.

    The U.S. science team is located at NASA's Jet Propulsion Laboratory, Pasadena, Calif. The Terra mission is part of NASA's Science Mission Directorate.

  9. Long Valley Coring Project

    USGS Publications Warehouse

    Sass, John; Finger, John; McConnel, Vicki

    1998-01-01

    In December 1997, the California Energy Commission (CEC) agreed to provide funding for Phase III continued drilling of the Long Valley Exploratory Well (LVEW) near Mammoth Lakes, CA, from its present depth. The CEC contribution of $1 million completes a funding package of $2 million from a variety of sources, which will allow the well to be cored continuously to a depth of between 11,500 and 12,500 feet. The core recovered from Phase III will be crucial to understanding the origin and history of the hydrothermal systems responsible for the filling of fractures in the basement rock. The borehole may penetrate the metamorphic roof of the large magmatic complex that has fed the volcanism responsible for the caldera and subsequent activity.

  10. Death Valley, California

    NASA Technical Reports Server (NTRS)

    1994-01-01

    This is an image of Death Valley, California, centered at 36.629 degrees north latitude, 117.069 degrees west longitude. The image shows Furnace Creek alluvial fan and Furnace Creek Ranch at the far right, and the sand dunes near Stove Pipe Wells at the center. The dark fork-shaped feature between Furnace Creek fan and the dunes is a smooth flood-plain which encloses Cottonball Basin. The bright dots near the center of the image are corner refectors that have been set-up to calibrate the radar as the Shuttle passes overhead with the SIR-C/X-SAR system. The Jet Propulsion Laboratory alternative photo number is P-43883.

  11. Railroad Valley, Nevada

    NASA Image and Video Library

    2002-02-01

    Information from images of Railroad Valley, Nevada captured on August 17, 2001 by the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) may provide a powerful tool for monitoring crop health and maintenance procedures. These images cover an area of north central Nevada. The top image shows irrigated fields, with healthy vegetation in red. The middle image highlights the amount of vegetation. The color code shows highest vegetation content in red, orange, yellow, green, blue, and purple and the lowest in black. The final image is a thermal infrared channel, with warmer temperatures in white and colder in black. In the thermal image, the northernmost and westernmost fields are markedly colder on their northwest areas, even though no differences are seen in the visible image or the second, Vegetation Index image. This can be attributed to the presence of excess water, which can lead to crop damage. http://photojournal.jpl.nasa.gov/catalog/PIA03463

  12. Death Valley, California

    NASA Technical Reports Server (NTRS)

    1994-01-01

    This is an image of Death Valley, California, centered at 36.629 degrees north latitude, 117.069 degrees west longitude. The image shows Furnace Creek alluvial fan and Furnace Creek Ranch at the far right, and the sand dunes near Stove Pipe Wells at the center. The dark fork-shaped feature between Furnace Creek fan and the dunes is a smooth flood-plain which encloses Cottonball Basin. The bright dots near the center of the image are corner refectors that have been set-up to calibrate the radar as the Shuttle passes overhead with the SIR-C/X-SAR system. The Jet Propulsion Laboratory alternative photo number is P-43883.

  13. Coachella Valley, CA

    NASA Image and Video Library

    2001-10-22

    These band composites, acquired on June 4, 2000, cover a 11 by 13.5 km sub-scene in the Coachella Valley, CA. The area is shown by the yellow box on the full scene in the LOWER RIGHT corner, northwest of the Salton Sea. This is a major agricultural region of California, growing fruit and produce throughout the year. Different combinations of ASTER bands help identify the different crop types. UPPER LEFT: bands 3, 2, 1 as red, green, and blue (RGB); UPPER RIGHT: bands 4, 2, 1 as RGB; LOWER LEFT: bands 4, 3, 2 as RGB. The image is centered at 33.6 degrees north latitude, 116.1 degrees west longitude. http://photojournal.jpl.nasa.gov/catalog/PIA11161

  14. Valley development on Hawaiian volcanoes

    NASA Technical Reports Server (NTRS)

    Baker, Victor R.; Gulick, Virginia C.

    1987-01-01

    Work in progress on Hawaiian drainage evolution indicates an important potential for understanding drainage development on Mars. Similar to Mars, the Hawaiian valleys were initiated by surface runoff, subsequently enlarged by groundwater sapping, and eventually stabilized as aquifers were depleted. Quantitative geomorphic measurements were used to evaluate the following factors in Hawaiian drainage evolution: climate, stream processes, and time. In comparing regions of similar climate, drainage density shows a general increase with the age of the volcani island. With age and climate held constant, sapping dominated valleys, in contrast to runoff-dominated valleys, display the following: lower drainage densities, higher ratios of valley floor width to valley height, and more positive profile concavities. Studies of stream junction angles indicate increasing junction angles with time on the drier leeward sides of the major islands. The quantitative geomorphic studies and earlier field work yielded important insights for Martian geomorphology. The importance of ash mantling in controlling infiltration on Hawaii also seems to apply to Mars. The Hawaiian valley also have implications for the valley networks of Martian heavily cratered terrains.

  15. Valley development on Hawaiian volcanoes

    NASA Astrophysics Data System (ADS)

    Baker, Victor R.; Gulick, Virginia C.

    1987-05-01

    Work in progress on Hawaiian drainage evolution indicates an important potential for understanding drainage development on Mars. Similar to Mars, the Hawaiian valleys were initiated by surface runoff, subsequently enlarged by groundwater sapping, and eventually stabilized as aquifers were depleted. Quantitative geomorphic measurements were used to evaluate the following factors in Hawaiian drainage evolution: climate, stream processes, and time. In comparing regions of similar climate, drainage density shows a general increase with the age of the volcani island. With age and climate held constant, sapping dominated valleys, in contrast to runoff-dominated valleys, display the following: lower drainage densities, higher ratios of valley floor width to valley height, and more positive profile concavities. Studies of stream junction angles indicate increasing junction angles with time on the drier leeward sides of the major islands. The quantitative geomorphic studies and earlier field work yielded important insights for Martian geomorphology. The importance of ash mantling in controlling infiltration on Hawaii also seems to apply to Mars. The Hawaiian valley also have implications for the valley networks of Martian heavily cratered terrains.

  16. Rift Valley fever.

    PubMed

    Paweska, J T

    2015-08-01

    Rift Valley fever (RVF) is a mosquito-borne zoonotic viral disease affecting domestic and wild ruminants, camels and humans. The causative agent of RVF, the RVF virus (RVFV), has the capacity to cause large and severe outbreaks in animal and human populations and to cross significant natural geographic barriers. Rift Valley fever is usually inapparent in non-pregnant adult animals, but pregnant animals and newborns can be severely affected; outbreaks are characterised by a sudden onset of abortions and high neonatal mortality. The majority of human infections are subclinical or associated with moderate to severe, non-fatal, febrile illness, but some patients may develop a haemorrhagic syndrome and/or ocular and neurological lesions. In both animals and humans, the primary site of RVFV replication and tissue pathology is the liver. Outbreaks of RVF are associated with persistent high rainfalls leading to massive flooding and the emergence of large numbers of competent mosquito vectors that transmit the virus to a wide range of susceptible vertebrate species. Outbreaks of RVF have devastating economic effects on countries for which animal trade constitutes the main source of national revenue. The propensity of the virus to spread into new territories and re-emerge in traditionally endemic regions, where it causes large outbreaks in human and animal populations, presents a formidable challenge for public and veterinary health authorities. The presence of competent mosquito vectors in RVF-free countries, the wide range of mammals susceptible to the virus, altering land use, the global changes in climate, and increased animal trade and travel are some of the factors which might contribute to international spread of RVF.

  17. Development of Enzyme-Linked Immunosorbent Assays Using Expressed Proteins of Rift Valley Fever Virus

    USDA-ARS?s Scientific Manuscript database

    Rift Valley fever virus (RVFV) is a member of the genus Phlebovirus, family Bunyaviridae that can cause severe disease in both humans and animals. The disease is enzootic in sub-Saharan Africa and RVFV epidemics/epizootics occur periodically, primarily in eastern and southern Africa. Since the virus...

  18. 75 FR 3946 - Tennessee Valley Authority; Establishment of Atomic Safety and Licensing Board

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-01-25

    ... Bellefonte Efficiency and Sustainability Team, and the Southern Alliance for Clean Energy in response to a... From the Federal Register Online via the Government Publishing Office NUCLEAR REGULATORY... following proceeding: Tennessee Valley Authority (Bellefonte Nuclear Plant, Units 1 and 2) This proceeding...

  19. Crown size relationships for black willow in the Lower Mississippi Alluvial Valley

    Treesearch

    Jamie L. Schuler; Bradley Woods; Joshua Adams; Ray Souter

    2015-01-01

    Growing space requirements derived from maximum and minimum crown sizes have been identified for many southern hardwood species. These requirements help managers assess stocking levels, schedule intermediate treatments, and even assist in determining planting densities. Throughout the Mississippi Alluvial Valley, black willow (Salix nigra Marsh.) stands are common...

  20. Salton Sea and Imperial Valley, California as seen from the Apollo 7 spacecra

    NASA Technical Reports Server (NTRS)

    1968-01-01

    Salton Sea and Imperial Valley area of southern California, including a portion of northern Baja California, Mexico, as seen from the Apollo 7 spacecraft during its 17th revolution of the earth. Photographed from an altitude of 125 nautical miles, at ground elapsed time of 27 hours.

  1. Specters of Waste in India's "Silicon Valley": The Underside of Bangalore's Hi-Tech Economy

    ERIC Educational Resources Information Center

    Narayanareddy, Rajyashree

    2011-01-01

    The southern Indian city of Bangalore is extolled as India's "Silicon Valley," emerging over the past decade as a premier site for capital flows into India's Information Technology (IT) sector. In the dominant narrative of globalization Bangalore is lauded as an aspiring "global city" that attracts sizeable quantities of…

  2. Specters of Waste in India's "Silicon Valley": The Underside of Bangalore's Hi-Tech Economy

    ERIC Educational Resources Information Center

    Narayanareddy, Rajyashree

    2011-01-01

    The southern Indian city of Bangalore is extolled as India's "Silicon Valley," emerging over the past decade as a premier site for capital flows into India's Information Technology (IT) sector. In the dominant narrative of globalization Bangalore is lauded as an aspiring "global city" that attracts sizeable quantities of…

  3. Releases of exotic parasitoids of Bemisia tabaci in San Joaquin Valley, California

    USDA-ARS?s Scientific Manuscript database

    In 1991, Bemisia tabaci was reported in the southern San Joaquin Valley infesting crops outside of greenhouses for the first time. From 1994 to 1996, 24 species/ strains of imported aphelinids, primarily species of Eretmocerus, were released in urban and agricultural settings for control of this whi...

  4. Testing a Mars science outpost in the Antarctic dry valleys

    NASA Technical Reports Server (NTRS)

    Andersen, D. T.; Mckay, C. P.; Wharton, R. A.; Rummel, J. D.

    1992-01-01

    Field research conducted in the Antarctic has been providing insights about the nature of Mars in the science disciplines of exobiology and geology. Located in the McMurdo Dry Valleys of southern Victoria Land (160 deg and 164 deg E longitude and 76 deg 30 min and 78 deg 30 min S latitude), research outposts are inhabited by teams of 4-6 scientists. It is proposed that the design of these outposts be expanded to enable meaningful tests of many of the systems that will be needed for the successful conduct of exploration activities on Mars. Although there are some important differences between the environment in the Antarctic dry valleys and on Mars, the many similarities and particularly the field science activities, make the dry valleys a useful terrestrial analog to conditions on Mars. Three areas have been identified for testing at a small science outpost in the dry valleys: (1) studying human factors and physiology in an isolated environment; (2) testing emerging technologies (e.g. innovative power management systems, advanced life support facilities including partial bioregenerative life support systems for water recycling and food growth, telerobotics, etc.); and (3) conducting basic scientific research that will enhance understanding of Mars while contributing to the planning for human exploration. It is suggested that an important early result of a Mars habitat program will be the experience gained by interfacing humans and their supporting technology in a remote and stressful environment.

  5. Testing a Mars science outpost in the Antarctic dry valleys.

    PubMed

    Andersen, D T; McKay, C P; Wharton, R A; Rummel, J D

    1992-01-01

    Field research conducted in the Antarctic has been providing insights about the nature of Mars in the science disciplines of exobiology and geology. Located in the McMurdo Dry Valleys of southern Victoria Land (160 degrees and 164 degrees E longitude and 76 degrees 30' and 78 degrees 30' S latitude), research outposts are inhabited by teams of 4-6 scientists. We propose that the design of these outposts be expanded to enable meaningful tests of many of the systems that will be needed for the successful conduct of exploration activities on Mars. Although there are some important differences between the environment in the Antarctic dry valleys and on Mars, the many similarities and particularly the field science activities, make the dry valleys a useful terrestrial analog to conditions on Mars. Three areas have been identified for testing at a small science outpost in the dry valleys; 1) studying human factors and physiology in an isolated environment; 2) testing emerging technologies (e.g., innovative power management systems, advanced life support facilities including partial bioregenerative life support systems for water recycling and food growth, telerobotics, etc.); and 3) conducting basic scientific research that will enhance our understanding of Mars while contributing to the planning for human exploration. We suggest that an important early result of a Mars habitat program will be the experience gained by interfacing humans and their supporting technology in a remote and stressful environment.

  6. Testing a Mars science outpost in the Antarctic dry valleys

    NASA Technical Reports Server (NTRS)

    Andersen, D. T.; Mckay, C. P.; Wharton, R. A.; Rummel, J. D.

    1992-01-01

    Field research conducted in the Antarctic has been providing insights about the nature of Mars in the science disciplines of exobiology and geology. Located in the McMurdo Dry Valleys of southern Victoria Land (160 deg and 164 deg E longitude and 76 deg 30 min and 78 deg 30 min S latitude), research outposts are inhabited by teams of 4-6 scientists. It is proposed that the design of these outposts be expanded to enable meaningful tests of many of the systems that will be needed for the successful conduct of exploration activities on Mars. Although there are some important differences between the environment in the Antarctic dry valleys and on Mars, the many similarities and particularly the field science activities, make the dry valleys a useful terrestrial analog to conditions on Mars. Three areas have been identified for testing at a small science outpost in the dry valleys: (1) studying human factors and physiology in an isolated environment; (2) testing emerging technologies (e.g. innovative power management systems, advanced life support facilities including partial bioregenerative life support systems for water recycling and food growth, telerobotics, etc.); and (3) conducting basic scientific research that will enhance understanding of Mars while contributing to the planning for human exploration. It is suggested that an important early result of a Mars habitat program will be the experience gained by interfacing humans and their supporting technology in a remote and stressful environment.

  7. 27 CFR 9.82 - Potter Valley.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2010-04-01 2010-04-01 false Potter Valley. 9.82... Potter Valley. (a) Name. The name of the viticultural area described in this section is “Potter Valley.” (b) Approved map. The approved maps for the Potter Valley viticultural area are the U.S.G.S....

  8. 27 CFR 9.154 - Chiles Valley.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2011-04-01 2011-04-01 false Chiles Valley. 9.154... Chiles Valley. (a) Name. The name of the viticultural area described in this section is “Chiles Valley.” (b) Approved maps. The appropriate maps for determining the boundary of the Chiles Valley...

  9. Ground-water resources of Pavant Valley, Utah

    USGS Publications Warehouse

    Mower, R.W.

    1965-01-01

    from the recharge areas near the mountains, it becomes confined beneath clay beds; thus artesian conditions prevail in the lower parts of the valley. Although as many as 12 saturated beds of sand and gravel are penetrated in drilling wells to depths of 800 feet, they constitute, generally, one aquifer. The beds of coarser material are interconnected laterally, and the confining beds between them are not perfect aquicludes but merely impede the vertical movement of water. Artesian pressure increases with depth; thus, there is a continual upward flow of water from the lowest to the highest aquifer, and water not withdrawn through wells is discharged at the land surface or into basalt flows along the western edge of the valley. Most recharge to the sand and gravel aquifers enters the ground on the alluvial fans as percolation from streams, irrigation ditches, and irrigated fields. Some recharge results from underflow from the canyons and the face of the mountains and also from precipitation on the alluvial fans. Leakage from the Central Utah Canal is a major source of recharge to alluvial aquifers in the northern half of the valley. The Pavant Flow in the western part of the valley and the basalt underlying the area west of the Black Rock Volcano in the southern part are both major unconfined basalt aquifers. The Pavant Flow is recharged by upward leakage of water from the underlying artesian aquifer, by percolation of irrigation water, by water moving laterally in shallow sand and gravel deposits, and by precipitation on outcrops along the western side of the valley. The basalt underlying the area west of the Black Rock Volcano is recharged by precipitation in the mountains, leakage from the artesian aquifer, and percolation of irrigation water. The ,basalt ,aquifers are relatively thin, averaging 30-60 feet in thickness where -they supply water to irrigation wells. The valley is divided into six districts based on geologic and hydrologic diffe

  10. Researching Indigenous Indians in Southern California: Commentary, Bibliography, and Online Resources

    ERIC Educational Resources Information Center

    Sutton, Imre

    2006-01-01

    This article seeks to present a continuing bibliography of research on Southern California Indians from the past 20 years, and sometimes beyond. The coverage reaches outside the variably defined bounds of Southern California so that it includes peripheral groups such as the Timbisha Shoshone of Death Valley and one or more groups in the Owens…

  11. Researching Indigenous Indians in Southern California: Commentary, Bibliography, and Online Resources

    ERIC Educational Resources Information Center

    Sutton, Imre

    2006-01-01

    This article seeks to present a continuing bibliography of research on Southern California Indians from the past 20 years, and sometimes beyond. The coverage reaches outside the variably defined bounds of Southern California so that it includes peripheral groups such as the Timbisha Shoshone of Death Valley and one or more groups in the Owens…

  12. Flood Tolerance and Related Characteristics of Trees of the Bottomland Forests of the Southern United States

    Treesearch

    J. Sid McKnight; Donal D. Hook; O. Gordon Landgon; Robert L. Johnson

    1980-01-01

    The Southern bottomland forests encompass about 12.5 million hectares (30.8 million acres) from Virginia, south to the sub-tropical hardwood forests of south Florida, west to eastern Texas and Oklahoma, and north up the Mississippi River Valley to southern Illinois and Indiana.

  13. Southern Exposure.

    ERIC Educational Resources Information Center

    Schueler, Donald G.

    1992-01-01

    Discusses results of a Green Index, published by the Institute for Southern Studies, that ranks the 50 states on the basis of 256 environmental indicators. Explores how and why the deep South states are all at the bottom of the list. A vignette provides a comparison between state hazardous waste generation and spending on waste management. (MCO)

  14. Paleogeomorphology of the early Colorado River inferred from relationships in Mohave and Cottonwood Valleys, Arizona, California and Nevada

    USGS Publications Warehouse

    Pearthree, Philip; House, Kyle

    2014-01-01

    Geologic investigations of late Miocene–early Pliocene deposits in Mohave and Cottonwood valleys provide important insights into the early evolution of the lower Colorado River system. In the latest Miocene these valleys were separate depocenters; the floor of Cottonwood Valley was ∼200 m higher than the floor of Mohave Valley. When Colorado River water arrived from the north after 5.6 Ma, a shallow lake in Cottonwood Valley spilled into Mohave Valley, and the river then filled both valleys to ∼560 m above sea level (asl) and overtopped the bedrock divide at the southern end of Mohave Valley. Sediment-starved water spilling to the south gradually eroded the outlet as siliciclastic Bouse deposits filled the lake upstream. When sediment accumulation reached the elevation of the lowering outlet, continued erosion of the outlet resulted in recycling of stored lacustrine sediment into downstream basins; depth of erosion of the outlet and upstream basins was limited by the water levels in downstream basins. The water level in the southern Bouse basin was ∼300 m asl (modern elevation) at 4.8 Ma. It must have drained and been eroded to a level <150 m asl soon after that to allow for deep erosion of bedrock divides and basins upstream, leading to removal of large volumes of Bouse sediment prior to massive early Pliocene Colorado River aggradation. Abrupt lowering of regional base level due to spilling of a southern Bouse lake to the Gulf of California could have driven observed upstream river incision without uplift. Rapid uplift of the entire region immediately after 4.8 Ma would have been required to drive upstream incision if the southern Bouse was an estuary.

  15. Accelerating optimization by tracing valley

    NASA Astrophysics Data System (ADS)

    Li, Qing-Xiao; He, Rong-Qiang; Lu, Zhong-Yi

    2016-06-01

    We propose an algorithm to accelerate optimization when an objective function locally resembles a long narrow valley. In such a case, a conventional optimization algorithm usually wanders with too many tiny steps in the valley. The new algorithm approximates the valley bottom locally by a parabola that is obtained by fitting a set of successive points generated recently by a conventional optimization method. Then large steps are taken along the parabola, accompanied by fine adjustment to trace the valley bottom. The effectiveness of the new algorithm has been demonstrated by accelerating the Newton trust-region minimization method and the Levenberg-Marquardt method on the nonlinear fitting problem in exact diagonalization dynamical mean-field theory and on the classic minimization problem of the Rosenbrock's function. Many times speedup has been achieved for both problems, showing the high efficiency of the new algorithm.

  16. Dawn in the Apollo Valley

    NASA Image and Video Library

    2013-12-18

    Beam Wave Guide antennas at Goldstone, known as the Beam Waveguide Cluster. They are located in an area at Goldstone called Apollo Valley. The Goldstone Deep Space Communications Complex is located in the Mojave Desert in California, USA.

  17. Ground water in the San Joaquin Valley, California

    USGS Publications Warehouse

    Kunkel, Fred; Hofman, Walter

    1966-01-01

    Ladies and gentlemen, it is a pleasure to be invited to attend this Irrigation Institute conference and to describe the Geological Survey's program of ground-water studies in the San Joaquin Valley. The U.S. Geological Survey has been making water-resources studies in cooperation with the State of California and other agencies in California for more than 70 years. Three of the earliest Geological Survey Water-Supply Papers--numbers 17, 18, and 19--published in 1898 and 1899, describe "Irrigation near Bakersfield," "Irrigation near Fresno," and "Irrigation near Merced." However, the first Survey report on ground-water occurrence in the San Joaquin Valley was "Ground Water in the San Joaquin Valley," by Mendenhall and others. The fieldwork was done from 1905 to 1910, and the report was published in 1916 as U.S. Geological Survey Water-Supply Paper 398.The current series of ground-water studies in the San Joaquin Valley was begun in 1952 as part of the California Department of Water Resources-U.S. Geological Survey cooperative water-resources program. The first report of this series is Geological Survey Water-Supply Paper 1469, "Ground-Water Conditions and Storage Capacity in the San Joaquin Valley." Other reports are Water-Supply Paper 1618, "Use of Ground-Water Reservoirs for Storage of Surface Water in the San Joaquin Valley;" Water-Supply Paper 1656, "Geology and Ground-Water Features of the Edison-Maricopa Area;" Water-Supply Paper 1360-G, "Ground- Water Conditions in the Mendota-Huron Area;" Water-Supply Paper 1457, "Ground-Water Conditions in the Avenal-McKittrick Area;" and an open-file report, "Geology, Hydrology, and Quality of Water in the Terra Bella-Lost Hills Area."In addition to the preceding published reports, ground-water studies currently are being made of the Kern Fan area, the Hanford- Visalia area, the Fresno area, the Merced area, and of the clays of Tulare Lake. Also, detailed studies of both shallow and deep subsidence in the southern part of

  18. Revisiting the Submerged Paleo Elbe Valley (S North Sea) with High-Resolution Shallow Seismics

    NASA Astrophysics Data System (ADS)

    Papenmeier, S.; Hass, H. C.

    2014-12-01

    The Elbe paleo valley is the most prominent subsurface structure in the southern North Sea (~10,000 km²) and constitutes an important part of Germany's largest marine Natura 2000-Reserve "Sylter Außenriff" (European environmental protection area). It is supposed that the valley was formed by epeirogenic movement during the Tertiary. The depression developed to its present form during the Weichselian sea-level lowstand (-130 m below present). Melt waters that discharged in north-westerly directions fed the paleo Elbe at that time. During the Holocene the valley drowned in the rising sea. A narrow raster of new shallow seismic data combined with high resolution sidescan sonar data is used to shed new light on the Holocene development of the paleo Elbe valley and its adjacent regions in detail. Cross sections distributed with transect distances of 400 and 800 m, respectively, over a length of 100 km (approximately one third of the total valley length) enable a good comprehensive analysis of the historical process of sedimentary valley infill and coastal evolution with the successive Holocene sea level rise. The eastern flank of the valley is characterized by a relatively steep slope with one or more terraces, representing moraine deposits which are today still present at the seafloor surface, partly covered with Holocene marine deposits. The western slip-off slope of the valley is much smoother than the eastern undercut slope. West of the valley, sediment cores show peat and tidal flat sediments. Shallow seismic data show the base of the valley. There are conspicuous internal seismic reflectors above the base, inclined in northeastern direction. They indicate a sedimentary infill of the valley from the southwest when the southern part of the Dogger Bank was flooded during the early Holocene sea-level rise. In this process the steeper eastern slope acted as a natural barrier towards the northeast, averted sediment transport beyond the eastern boundary of the paleo

  19. [The Southern Sierra Nevada continental dynamics project]. Final technical report

    SciTech Connect

    Clayton, R.W.; Saleeby, J.B.

    1997-12-16

    The main objective of this study was to determine whether or not the Southern Sierra Nevada Mountain Range is supported by a crustal root. A secondary goal was to evaluate the relationship between the Sierra Nevada Range and the adjoining Death Valley extensional province. As part of the project, two seismic profiles were executed. The first was a north-south profile running from Ridgecrest to Chafant Valley. The second was an east-west profile from Death Valley to Coalinga. An NPE shot was recorded on the east-west receiver line, and the data were analyzed by forward modeling with a staggered-grid finite-difference code. Concurrently, the authors initiated an in-depth study of lower crustal and upper mantle xenoliths hosted by Neogene volcanic rocks of the central and southern Sierra Nevada region. This initial work focused on thermobarometric estimates of representative xenolith samples aimed at understanding the vertical composition of the Sierra Nevada lithosphere.

  20. Modelling photochemistry in alpine valleys

    NASA Astrophysics Data System (ADS)

    Brulfert, G.; Chemel, C.; Chaxel, E.; Chollet, J. P.

    2005-03-01

    Road traffic is a serious problem in the Chamonix Valley, France: traffic, noise and above all air pollution worry the inhabitants. The big fire in the Mont-Blanc tunnel made it possible, in the framework of the POVA project (POllution in Alpine Valleys), to undertake measurement campaigns with and without heavy-vehicle traffic through the valley, towards Italy (before and after the tunnel re-opening). Modelling in POVA should make it possible to explain the processes leading to episodes of atmospheric pollution, both in summer and in winter. Atmospheric prediction model ARPS 4.5.2 (Advanced Regional Prediction System), developed at the CAPS (Center for Analysis and Prediction of Storms) of the University of Oklahoma, enables to resolve the dynamics above a complex terrain. This model is coupled to the TAPOM 1.5.2 atmospheric chemistry (Transport and Air POllution Model) code developed at the Air and Soil Pollution Laboratory of the Ecole Polytechnique Fédérale de Lausanne. The numerical codes MM5 and CHIMERE are used to compute large scale boundary forcing. Using 300-m grid cells to calculate the dynamics and the reactive chemistry makes possible to accurately represent the dynamics in the valley (slope and valley winds) and to process chemistry at fine scale. Validation of campaign days allows to study chemistry indicators in the valley. NOy according to O3 reduction demonstrates a VOC controlled regime, different from the NOx controlled regime expected and observed in the nearby city of Grenoble.

  1. [Rift Valley fever].

    PubMed

    Pépin, M

    2011-06-01

    Rift Valley Fever (RVF) is a zoonotic arbovirosis. Among animals, it mainly affects ruminants, causing abortions in gravid females and mortality among young animals. In humans, RVF virus infection is usually asymptomatic or characterized by a moderate fever. However, in 1 to 3% of cases, more severe forms of the disease (hepatitis, encephalitis, retinitis, hemorrhagic fever) can lead to the death of infected individuals or to major sequels. The RVF virus (Bunyaviridae, genus Phlebovirus) was identified for the first time in the 1930s in Kenya. It then spread over almost all African countries, sometimes causing major epizootics/epidemics. In 2000, the virus was carried out of Africa, in the Middle East Arabian Peninsula. In 2007-2008, Eastern-African countries, including Madagascar, reported significant episodes of RVF virus, this was also the case for the Comoros archipelago and the French island of Mayotte. This ability to spread associated with many vectors, including in Europe, and high viral loads in infected animals led the health authorities worldwide to warn about the potential emergence of RVF virus in areas with a temperate climate. The awareness has increased in recent years with climate changes, which may possibly modify the vector distribution and competence, and prompted many RVF virus-free countries to better prepare for a potential implantation of RVF. Copyright © 2011 Elsevier Masson SAS. All rights reserved.

  2. Railroad Valley, Nevada

    NASA Technical Reports Server (NTRS)

    2001-01-01

    Information from images of Railroad Valley, Nevada captured on August 17,2001 by the Advanced Spaceborne Thermal Emission and Reflection Radiometer(ASTER) may provide a powerful tool for monitoring crop health and maintenance procedures.

    These images cover an area of north central Nevada. The top image shows irrigated fields, with healthy vegetation in red. The middle image highlights the amount of vegetation. The color code shows highest vegetation content in red, orange, yellow, green, blue, and purple and the lowest in black. The final image is a thermal infrared channel, with warmer temperatures in white and colder in black.

    In the thermal image, the northernmost and westernmost fields are markedly colder on their northwest areas, even though no differences are seen in the visible image or the second, Vegetation Index image. This can be attributed to the presence of excess water, which can lead to crop damage.

    The Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER)is an imaging instrument that is flying on Terra, a satellite launched in December 1999 as part of NASA's Earth Observing System (EOS). The instrument is being used to obtain detailed maps of land surface temperature, emissivity, reflectance and elevation. The Earth Observing System (EOS) platforms are part of NASA's Earth Science Enterprise, whose goal is to obtain a better understanding of the interactions between the biosphere, hydrosphere, lithosphere and atmosphere.

    NASA's Jet Propulsion Laboratory is a division of the California Institute of Technology, Pasadena.

  3. SRTM Perspective View with Landsat Overlay: San Joaquin Valley, California

    NASA Technical Reports Server (NTRS)

    2000-01-01

    San Joaquin, the name given to the southern portion of California's vast Central Valley, has been called the world's richest agricultural valley. In this perspective view generated using data from the Shuttle Radar Topography Mission and an enhanced Landsat image, we are looking toward the southwest over a checkerboard pattern of agricultural fields. Mt. Pinos, a popular location for stargazing at 2,692 meters (8,831 feet) looms above the valley floor and is visible on the left side of the image. The productive southern San Joaquin is in reality a desert, averaging less than 12.7 cm (5 inches) of rain per year. Through canals and irrigation, the region nurtures some two hundred crops including grapes, figs, apricots, oranges, and more than 4,047 square-km (1,000,000 acres) of cotton. The California Aqueduct, transporting water from the Sacramento River Delta through the San Joaquin, runs along the base of the low-lying Wheeler Ridge on the left side of the image. The valley is not all agriculture though. Kern County, near the valley's southern end, is the United States' number one oil producing county, and actually produces more crude oil than Oklahoma. For visualization purposes, topographic heights displayed in this image are exaggerated two times. Colors, from Landsat data, approximate natural color.

    The elevation data used in this image was acquired by SRTM aboard the Space Shuttle Endeavour, launched on February 11, 2000. SRTM used the same radar instrument that comprised the Spaceborne Imaging Radar-C/X-Band Synthetic Aperture Radar (SIR-C/X-SAR) that flew twice on Endeavour in 1994. SRTM was designed to collect three-dimensional measurements of Earth's land surface. To collect the 3-D SRTM data, engineers added a mast 60 meters (about 200 feet)long, installed additional C-band and X-band antennas, and improved tracking and navigation devices. The mission is a cooperative project between the NASA, the National Imagery and Mapping Agency (NIMA) of the U

  4. SRTM Perspective View with Landsat Overlay: San Joaquin Valley, California

    NASA Technical Reports Server (NTRS)

    2000-01-01

    San Joaquin, the name given to the southern portion of California's vast Central Valley, has been called the world's richest agricultural valley. In this perspective view generated using data from the Shuttle Radar Topography Mission and an enhanced Landsat image, we are looking toward the southwest over a checkerboard pattern of agricultural fields. Mt. Pinos, a popular location for stargazing at 2,692 meters (8,831 feet) looms above the valley floor and is visible on the left side of the image. The productive southern San Joaquin is in reality a desert, averaging less than 12.7 cm (5 inches) of rain per year. Through canals and irrigation, the region nurtures some two hundred crops including grapes, figs, apricots, oranges, and more than 4,047 square-km (1,000,000 acres) of cotton. The California Aqueduct, transporting water from the Sacramento River Delta through the San Joaquin, runs along the base of the low-lying Wheeler Ridge on the left side of the image. The valley is not all agriculture though. Kern County, near the valley's southern end, is the United States' number one oil producing county, and actually produces more crude oil than Oklahoma. For visualization purposes, topographic heights displayed in this image are exaggerated two times. Colors, from Landsat data, approximate natural color.

    The elevation data used in this image was acquired by SRTM aboard the Space Shuttle Endeavour, launched on February 11, 2000. SRTM used the same radar instrument that comprised the Spaceborne Imaging Radar-C/X-Band Synthetic Aperture Radar (SIR-C/X-SAR) that flew twice on Endeavour in 1994. SRTM was designed to collect three-dimensional measurements of Earth's land surface. To collect the 3-D SRTM data, engineers added a mast 60 meters (about 200 feet)long, installed additional C-band and X-band antennas, and improved tracking and navigation devices. The mission is a cooperative project between the NASA, the National Imagery and Mapping Agency (NIMA) of the U

  5. Fog and Haze in California's San Joaquin Valley

    NASA Technical Reports Server (NTRS)

    2001-01-01

    This illustration features images of southern California and southwestern Nevada acquired on January 3, 2001 (Terra orbit 5569), and includes data from three of MISR's nine cameras. The San Joaquin Valley, which comprises the southern extent of California's Central Valley, covers much of the viewed area. Also visible are several of the Channel Islands near the bottom, and Mono and Walker Lakes, which stand out as darker patches near the top center, especially in the vertical and backward oblique images. Near the lower right of each image is the Los Angeles Basin, with the distinctive chevron shape of the Mojave Desert to its north.

    The Central Valley is a well-irrigated and richly productive agricultural area situated between the Coast Range and the snow-capped Sierra Nevadas. During the winter, the region is noted for its hazy overcasts and a low, thick ground fog known as the Tule. Owing to the effects of the atmosphere on reflected sunlight, dramatic differences in the MISR images are apparent as the angle of view changes. An area of thick, white fog in the San Joaquin Valley is visible in all three of the images. However, the pervasive haze that fills most of the valley is only slightly visible in the vertical view. At the oblique angles, the haze is highly distinguishable against the land surface background, particularly in the forward-viewing direction. Just above image center, the forward view also reveals bluish-tinged plumes near Lava Butte in Sequoia National Forest, where the National Interagency Coordination Center reported an active forest fire.

    The changing surface visibility in the multi-angle data allows us to derive the amount of atmospheric haze. In the lower right quadrant is a map of haze amount determined from automated processing of the MISR imagery. Low amounts of haze are shown in blue, and a variation in hue through shades of green, yellow, and red indicates progressively larger amounts of airborne particulates. Due to the

  6. New GPS Constraints On Owens Valley Fault Slip Rates

    NASA Astrophysics Data System (ADS)

    Jha, S.; Hammond, W. C.; Kreemer, C. W.; Blewitt, G.

    2009-12-01

    The Owens Valley fault (OVF) is one of several north- to northwest-striking faults that collectively accommodate ~10 mm/yr of dextral shear and extension across the southern Walker Lane/Eastern California Shear Zone (SWL). This zone, which lies east of the San Andreas Fault system and the Sierra Nevada microplate and north of the Garlock Fault, accommodates 20-25% of the Pacific/North America relative plate motion. The OVF strikes subparallel to principal regional faults to the east, including the Panamint Valley, Death Valley, and Fish Lake Valley fault zones, and is the site of an M 7.5 earthquake in 1872. Fault slip rates are a key input into seismic hazard modeling and can be estimated from GPS measurements that quantify the rate and pattern of interseismic crustal deformation. Earlier geodetic estimates based on campaign GPS are between ~2-8.5 mm/yr, while geologic estimates range from ~1 to 4 mm/yr. In the past several years, GPS constraints on crustal deformation of the SWL has improved though the southward extension of the MAGNET GPS network with 3 campaigns extending the time series to 4 years from 2005 to 2009, installation of EarthScope Plate Boundary Observatory, and longer time series on stations of the Basin and Range GPS network. These data have been analyzed using GIPSY-OASIS II with recently reprocessed orbits from the IGS analysis center at JPL. Our GPS processing now includes satellite and station antenna calibrations, random-walk tropospheric zenith delay and gradients using the GMF mapping function, second-order ionospheric corrections, global-scale ambiguity resolution using our custom Ambizap software, and our custom Great Basin spatially-filtered reference frame. These improved measurements justify a new look at rates across the OVF. We present a revised estimate for the slip rate by applying a block modeling methodology constrained by the new GPS data. Since the GPS data in this region are suspected to contain transient signals from post

  7. Hydrology of modern and late Holocene lakes, Death Valley, California

    SciTech Connect

    Grasso, D.N.

    1996-07-01

    Above-normal precipitation and surface-water runoff, which have been generally related to the cyclic recurrence of the El Nino-Southern Oscillation, have produced modern ephemeral lakes in the closed-basin Death Valley watershed. This study evaluates the regional hydroclimatic relations between precipitation, runoff, and lake transgressions in the Death Valley watershed. Recorded precipitation, runoff, and spring discharge data for the region are used in conjunction with a closed-basin, lake-water-budget equation to assess the relative contributions of water from these sources to modern lakes in Death Valley and to identify the requisite hydroclimatic changes for a late Holocene perennial lake in the valley. As part of the Yucca Mountain Site Characterization Program, an evaluation of the Quaternary regional paleoflood hydrology of the potential nuclear-waste repository site at Yucca Mountain, Nevada, was planned. The objectives of the evaluation were (1) to identify the locations and investigate the hydraulic characteristics of paleofloods and compare these with the locations and characteristics of modern floods, and (2) to evaluate the character and severity of past floods and debris flows to ascertain the potential future hazards to the potential repository during the pre-closure period (US Department of Energy, 1988). This study addresses the first of these objectives, and the second in part, by assessing and comparing the sizes, locations, and recurrence rates of modern, recorded (1962--83) floods and late Holocene paleofloods for the 8,533-mi{sup 2}, closed-basin, Death Valley watershed with its contributing drainage basins in the Yucca Mountain site area.

  8. Upper Neogene stratigraphy and tectonics of Death Valley - A review

    USGS Publications Warehouse

    Knott, J.R.; Sarna-Wojcicki, A. M.; Machette, M.N.; Klinger, R.E.

    2005-01-01

    New tephrochronologic, soil-stratigraphic and radiometric-dating studies over the last 10 years have generated a robust numerical stratigraphy for Upper Neogene sedimentary deposits throughout Death Valley. Critical to this improved stratigraphy are correlated or radiometrically-dated tephra beds and tuffs that range in age from > 3.58 Ma to < 1.1 ka. These tephra beds and tuffs establish relations among the Upper Pliocene to Middle Pleistocene sedimentary deposits at Furnace Creek basin, Nova basin, Ubehebe-Lake Rogers basin, Copper Canyon, Artists Drive, Kit Fox Hills, and Confidence Hills. New geologic formations have been described in the Confidence Hills and at Mormon Point. This new geochronology also establishes maximum and minimum ages for Quaternary alluvial fans and Lake Manly deposits. Facies associated with the tephra beds show that ???3.3 Ma the Furnace Creek basin was a northwest-southeast-trending lake flanked by alluvial fans. This paleolake extended from the Furnace Creek to Ubehebe. Based on the new stratigraphy, the Death Valley fault system can be divided into four main fault zones: the dextral, Quaternary-age Northern Death Valley fault zone; the dextral, pre-Quaternary Furnace Creek fault zone; the oblique-normal Black Mountains fault zone; and the dextral Southern Death Valley fault zone. Post -3.3 Ma geometric, structural, and kinematic changes in the Black Mountains and Towne Pass fault zones led to the break up of Furnace Creek basin and uplift of the Copper Canyon and Nova basins. Internal kinematics of northern Death Valley are interpreted as either rotation of blocks or normal slip along the northeast-southwest-trending Towne Pass and Tin Mountain fault zones within the Eastern California shear zone. ?? 2005 Elsevier B.V. All rights reserved.

  9. Cold air drainage flows subsidize montane valley ecosystem productivity.

    PubMed

    Novick, Kimberly A; Oishi, A Christopher; Miniat, Chelcy Ford

    2016-12-01

    In mountainous areas, cold air drainage from high to low elevations has pronounced effects on local temperature, which is a critical driver of many ecosystem processes, including carbon uptake and storage. Here, we leverage new approaches for interpreting ecosystem carbon flux observations in complex terrain to quantify the links between macro-climate condition, drainage flows, local microclimate, and ecosystem carbon cycling in a southern Appalachian valley. Data from multiple long-running climate stations and multiple eddy covariance flux towers are combined with simple models for ecosystem carbon fluxes. We show that cold air drainage into the valley suppresses local temperature by several degrees at night and for several hours before and after sunset, leading to reductions in growing season respiration on the order of ~8%. As a result, we estimate that drainage flows increase growing season and annual net carbon uptake in the valley by >10% and >15%, respectively, via effects on microclimate that are not be adequately represented in regional- and global-scale terrestrial ecosystem models. Analyses driven by chamber-based estimates of soil and plant respiration reveal cold air drainage effects on ecosystem respiration are dominated by reductions to the respiration of aboveground biomass. We further show that cold air drainage proceeds more readily when cloud cover and humidity are low, resulting in the greatest enhancements to net carbon uptake in the valley under clear, cloud-free (i.e., drought-like) conditions. This is a counterintuitive result that is neither observed nor predicted outside of the valley, where nocturnal temperature and respiration increase during dry periods. This result should motivate efforts to explore how topographic flows may buffer eco-physiological processes from macroscale climate change. © 2016 John Wiley & Sons Ltd.

  10. Southern Florida

    NASA Technical Reports Server (NTRS)

    2002-01-01

    Three fires (red dots) in southern Florida are visible in this true-color MODIS image acquired April 4, 2002. Also visible is the city of Miami, and the northern edge of Cuba, including the city of Havana. The bright blue-green colors in the waters of the Strait of Florida are due to the Sun's light reflected off of chlorophyll in marine phytoplankton.

  11. Southern Italy

    NASA Image and Video Library

    1973-06-22

    SL2-05-359 (22 June 1973) --- This rare cloud free view of southern Italy (41.0N, 16.0E) shows almost all of the famous `boot' configuration of the peninsula up to just north of Naples and Mount Vesuvius. The land mass of this historic peninsula contrasts sharply with the sparkling blue waters of the Mediterranean Sea. Photo credit: NASA

  12. Imperial Valley and Salton Sea, California

    NASA Technical Reports Server (NTRS)

    2002-01-01

    Southern California's Salton Sea is a prominent visual for astronauts. This large lake supports the rich agricultural fields of the Imperial, Coachella and Mexicali Valleys in the California and Mexico desert. The Salton Sea formed by accident in 1905 when an irrigation canal ruptured, allowing the Colorado River to flood the Salton Basin. Today the Sea performs an important function as the sink for agricultural runoff; water levels are maintained by the runoff from the surrounding agricultural valleys. The Salton Sea salinity is high-nearly 1/4 saltier than ocean water-but it remains an important stopover point for migratory water birds, including several endangered species. The region also experiences several environmental problems. The recent increased demands for the limited Colorado River water threatens the amount of water allowed to flow into the Salton Sea. Increased salinity and decreased water levels could trigger several regional environmental crises. The agricultural flow into the Sea includes nutrients and agricultural by-products, increasing the productivity and likelihood of algae blooms. This image shows either a bloom, or suspended sediment (usually highly organic) in the water that has been stirred up by winds. Additional information: The Salton Sea A Brief Description of Its Current Conditions, and Potential Remediation Projects and Land Use Across the U.S.-Mexico Border Astronaut photograph STS111-E-5224 was taken by the STS-111 Space Shuttle crew that recently returned from the International Space Station. The image was taken June 12, 2002 using a digital camera. The image was provided by the Earth Sciences and Image Analysis Laboratory at Johnson Space Center. Additional images taken by astronauts and cosmonauts can be viewed at the NASA-JSC Gateway to Astronaut Photography of Earth.

  13. View Back Uphill After Entering 'Perseverance Valley'

    NASA Image and Video Library

    2017-07-20

    This image from the navigation camera (Navcam) on the mast of NASA's Mars Exploration Rover Opportunity provides a look back to the crest of Endeavour Crater's rim after the rover began descending "Perseverance Valley" on the rim's inner slope. The Navcam took this image on July 18, 2017, during the 4,793rd Martian day, or sol, of Opportunity's work on Mars. Wheel tracks from the top of the rim to the rover are visible above the rear solar panel of the vehicle. For scale, the distance between tracks from right-side wheels and tracks from left-side wheels is about 3.3 feet (1 meter). The knob-topped cylinder mounted at the edge of the solar panel is the calibration target for Opportunity's panoramic camera (Pancam). Opportunity's location on Sol 4793 was a site within the upper end of Perseverance Valley that the rover reached with a drive of about 45 feet (13.8 meters) on July 7 (Sol 4782). The rover team chose this location for Opportunity to spend about three weeks during a driving moratorium for the Mars solar conjunction period. Mars solar conjunction occurs once about every 26 months when Mars passes nearly behind the sun, from Earth's perspective. The relative positions of the three bodies makes radio transmission of commands from Earth to Mars unreliable. One advantage of this chosen location for Opportunity is a slight northward tilt for the solar panels, which adds to their power output during these weeks of southern-hemisphere autumn when daily sunshine is diminishing. https://photojournal.jpl.nasa.gov/catalog/PIA21725

  14. Quaternary Geochronology, Paleontology, and Archaeology of the Upper San Pedro River Valley, Sonora, Mexico

    NASA Astrophysics Data System (ADS)

    Gaines, E. P.

    2013-12-01

    This poster presents the results of multi-disciplinary investigations of the preservation and extent of Quaternary fossil-bearing strata in the San Pedro River Valley in Sonora, Mexico. Geologic deposits in the portions of the San Pedro Valley in southern Arizona contain one of the best late Cenozoic fossil records known in North America and the best record of early humans and extinct mammals on the continent. The basin in the U.S. is one of the type locations for the Blancan Land Mammal Age. Hemiphilian and Irvingtonian fossils are common. Rancholabrean remains are widespread. Strata in the valley adjacent to the international border with Mexico have yielded the densest concentration of archaeological mammoth-kill sites known in the western hemisphere. Despite more than 60 years of research in the U.S., however, and the fact that over one third of the San Pedro River lies south of the international boundary, little has been known about the late Cenozoic geology of the valley in Mexico. The study reported here utilized extensive field survey, archaeological documentation, paleontological excavations, stratigraphic mapping and alluvial geochronology to determine the nature and extent of Quaternary fossil-bearing deposits in the portions of the San Pedro Valley in Sonora, Mexico. The results demonstrate that the Plio-Pleistocene fossil -bearing formations known from the valley in Arizona extend into the uppermost reaches of the valley in Mexico. Several new fossil sites were discovered that yielded the remains of Camelids, Equus, Mammuthus, and other Proboscidean species. Late Pleistocene archaeological remains were found on the surface of the surrounding uplands. AMS radiocarbon dating demonstrates the widespread preservation of middle- to late- Holocene deposits. However, the late Pleistocene deposits that contain the archaeological mammoth-kill sites in Arizona are absent in the valley in Mexico, and are now known to be restricted to relatively small portions of

  15. Young Mid-latitude Martian Valleys: Evidence from Newton and Gorgonum Basins

    NASA Astrophysics Data System (ADS)

    Howard, A. D.; Moore, J. M.

    2009-12-01

    The mid-latitudes of Mars feature distinctive landforms, including extensive mantling deposits, glacial and periglacial landforms, very young gullies on steep slopes, and sparse, shallowly-incised, fresh-appearing valleys discussed here. These mid-latitude valleys (MLVs) are distinct from the older, late Noachian to early Hesperian valley systems which are deeply dissected, generally of much larger spatial extent and which feature multiple tributaries. The older valley systems extend from equatorial to near-polar latitudes and are much more degraded than the MLVs. Although some MLVs involve rejuvenation of older valley networks, many MLVs are eroded into smooth or rolling slopes and intercrater terrain. The MLVs range from a few meters to more than 300 m in width, with nearly parallel valley walls and planforms that are locally sinuous. Valley floors appear to be nearly flat, sometimes exhibiting faint lineations. These features suggest that the MLVs in many cases are incised channels that were occupied at least intermittently by flows over the entire valley bottom. Particularly diagnostic MLVs occupy parts of the floors of the ~ 300 km Newton and the ~240 km Gorgonum basins on the southern highlands. In Newton basin the MLVs are sourced from the upper basin walls and flow radially inwards towards the basin center, extending across the smooth basin floor (which may have been the site of an earlier paleolake). Incised and depositional sections sometimes alternate in response to variations in basin slope. The valleys terminate in small fans. In some places the valleys appear to anastomose, but it is likely that the multiple valleys record successive flow diversions. There is no evidence that the valleys terminated in standing water in the basin center. MLVs in Gorgonum basin likewise are sourced from the upper basin walls and flow inward, but in this case the valleys disappear at the edge of what has previously been hypothesized to be a late stage, ice-covered lake

  16. The ValleyMorph Tool: An automated extraction tool for transverse topographic symmetry (T-) factor and valley width to valley height (Vf-) ratio

    NASA Astrophysics Data System (ADS)

    Daxberger, Heidi; Dalumpines, Ron; Scott, Darren M.; Riller, Ulrich

    2014-09-01

    In tectonically active regions on Earth, shallow-crustal deformation associated with seismic hazards may pose a threat to human life and property. The study of landform development, such as analysis of the valley width to valley height ratio (Vf-ratio) and the Transverse Topographic Symmetry Factor (T-factor), delineating drainage basin symmetry, can be used as a relative measure of tectonic activity along fault-bound mountain fronts. The fast evolution of digital elevation models (DEM) provides an ideal base for remotely-sensed tectonomorphic studies of large areas using Geographical Information Systems (GIS). However, a manual extraction of the above mentioned morphologic parameters may be tedious and very time consuming. Moreover, basic GIS software suites do not provide the necessary built-in functions. Therefore, we present a newly developed, Python based, ESRI ArcGIS compatible tool and stand-alone script, the ValleyMorph Tool. This tool facilitates an automated extraction of the Vf-ratio and the T-factor data for large regions. Using a digital elevation raster and watershed polygon files as input, the tool provides output in the form of several ArcGIS data tables and shapefiles, ideal for further data manipulation and computation. This coding enables an easy application among the ArcGIS user community and code conversion to earlier ArcGIS versions. The ValleyMorph Tool is easy to use due to a simple graphical user interface. The tool is tested for the southern Central Andes using a total of 3366 watersheds.

  17. Tennessee Valley and Eastern Kentucky Wind Working Group

    SciTech Connect

    Katie Stokes

    2012-05-03

    In December 2009, the Southern Alliance for Clean Energy (SACE), through a partnership with the Appalachian Regional Commission, EKPC, Kentucky's Department for Energy Development and Independence, SACE, Tennessee's Department of Environment and Conservation, and TVA, and through a contract with the Department of Energy, established the Tennessee Valley and Eastern Kentucky Wind Working Group (TVEKWWG). TVEKWWG consists of a strong network of people and organizations. Working together, they provide information to various organizations and stakeholders regarding the responsible development of wind power in the state. Members include representatives from utility interests, state and federal agencies, economic development organizations, non-government organizations, local decision makers, educational institutions, and wind industry representatives. The working group is facilitated by the Southern Alliance for Clean Energy. TVEKWWG supports the Department of Energy by helping educate and inform key stakeholders about wind energy in the state of Tennessee.

  18. Delta growth and river valleys: the influence of climate and sea level changes on the South Adriatic shelf (Mediterranean Sea)

    NASA Astrophysics Data System (ADS)

    Maselli, V.; Trincardi, F.; Asioli, A.; Ceregato, A.; Rizzetto, F.; Taviani, M.

    2014-09-01

    Incised valleys across continental margins represent the response of fluvial systems to changes in their equilibrium dynamics, mainly driven by base level fall forced by glacial-eustatic cycles. The Manfredonia Incised Valley formed during the last glacial sea level lowstand, when most of the southern Adriatic shelf was sub-aerially exposed but the outer shelf remained under water. The pronounced upstream deepening of the valley is ascribed to river incision of the MIS5e highstand coastal prism and related subaqueous clinoform under the influence of MIS5-4 sea level fluctuations, while the downstream shallowing and narrowing mainly reflects the impact of increased rates of sea level fall at the MIS3-2 transition on a flatter mid-outer shelf. Until 15 ka BP, the valley fed an asymmetric delta confined to the mid-outer shelf, testifying that continental and deep marine systems remained disconnected during the lowstand. Sea level rise reached the inner shelf during the Early Holocene, drowning the valley and leading to the formation of a sheltered embayment confined toward the land: at this time part of the incision remained underfilled with a marked bathymetric expression. This mini-basin was rapidly filled by sandy bayhead deltas, prograding from both the northern and southern sides of the valley. In this environment, protected by marine reworking and where sediment dispersal was less effective, the accommodation space was reduced and autogenic processes forced the formation of multiple and coalescing delta lobes. Bayhead delta progradations occurred in few centuries, between 8 and 7.2 ka cal BP, confirming the recent hypothesis that in this area the valley was filled during the formation of sapropel S1. This proximal valley fill, representing the very shallow-water equivalent of the cm-thick sapropel layers accumulated offshore in the deeper southern Adriatic basin, is of key importance in following the signature of the sapropel in a facies-tract ideally from the

  19. Dark Valley in Newton Crater

    NASA Technical Reports Server (NTRS)

    2003-01-01

    MGS MOC Release No. MOC2-418, 11 July 2003

    This Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) high resolution image shows part of a dark-floored valley system in northern Newton Crater. The valley might have been originally formed by liquid water; the dark material is probably sand that has blown into the valley in more recent times. The picture was acquired earlier this week on July 6, 2003, and is located near 39.2oS, 157.9oW. The picture covers an area 2.3 km (1.4 mi) across; sunlight illuminates the scene from the upper left.

  20. Channels and valleys on Mars

    NASA Technical Reports Server (NTRS)

    Baker, V. R.

    1983-01-01

    Tentative conclusions about the origins of channels and valleys on Mars based on the consensus of investigators who have studied the problem are presented. The morphology of outflow channels is described in detail, and the morphology, distribution, and genesis of Martian valleys are addressed. Secondary modification of channels and valleys by mass-wasting phenomena, eolian processes, cratering, and mantling by lava flows is discussed. The physics of the flows needed to account for the immense volumes of Martian outflow channels is considered in detail, including the possible influence of debris flows and mudflows, glaciers, and ice sheets. It is concluded that Mars once probably possessed an atmosphere with higher temperatures and pressures than at present which played an essential role in an active hydrological cycle.

  1. Groundwater formation of martian valleys

    USGS Publications Warehouse

    Malin, M.C.; Carr, M.H.

    1999-01-01

    The martian surface shows large outflow channels, widely accepted as having been formed by gigantic floods that could have occurred under climatic conditions like those seen today. Also present are branching valley networks that commonly have tributaries. These valleys are much smaller than the outflow channels and their origins and ages have been controversial. For example, they might have formed through slow erosion by water running across the surface, either early or late in Mars' history, possibly protected from harsh conditions by ice cover. Alternatively, they might have formed through groundwater or ground-ice processes that undermine the surface and cause collapse, again either early or late in Mars' history. Long-duration surface runoff would imply climatic conditions quite different from the present environment. Here we present high-resolution images of martian valleys that support the view that ground water played an important role in their formation, although we are unable as yet to establish when this occurred.

  2. Dark Valley in Newton Crater

    NASA Technical Reports Server (NTRS)

    2003-01-01

    MGS MOC Release No. MOC2-418, 11 July 2003

    This Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) high resolution image shows part of a dark-floored valley system in northern Newton Crater. The valley might have been originally formed by liquid water; the dark material is probably sand that has blown into the valley in more recent times. The picture was acquired earlier this week on July 6, 2003, and is located near 39.2oS, 157.9oW. The picture covers an area 2.3 km (1.4 mi) across; sunlight illuminates the scene from the upper left.

  3. Geological and geothermal investigation of the lower Wind River valley, southwestern Washington Cascade Range

    SciTech Connect

    Berri, D.A.; Korosec, M.A.

    1983-01-01

    The detailed geology of the lower Wind River valley is presented with emphasis on those factors that bear significantly on development of a geothermal resource. The lower Wind River drainage consists primarily of the Ohanapecosh Formation, an Oligocene unit that is recognized across the entire southern Washington Cascade Range. The formation is at least 300 m thick in the Wind River valley area. It consists largely of volcaniclastic sediments, with minor massive pyroclastic flows, volcanic breccias and lava flows. Low grade zeolite facies metamorphism during the Miocene led to formation of hydrothermal minerals in Ohanapecosh strata. Metamorphism probably occurred at less than 180{sup 0}C.

  4. Role of seismogenic processes in fault-rock development: An example from Death Valley, California

    NASA Astrophysics Data System (ADS)

    Pavlis, Terry L.; Serpa, Laura F.; Keener, Charles

    1993-03-01

    Fault rocks developed along the Mormon Point turtleback of southern Death Valley suggest that a jog in the oblique-slip Death Valley fault zone served as an ancient seismic barrier, where dominantly strike-slip ruptures were terminated at a dilatant jog. Dramatic spatial variations in fault-rock thickness and type within the bend are interpreted as the products of: (1) fault "overshoot," in which planar ruptures bypass the intersection of the two faults composing the bend and slice into the underlying footwall; and (2) implosion brecciation, in which coseismic ruptures arrested at a releasing bend in the fault lead to catastrophic collapse brecciation, fluid influx, and mineralization.

  5. Modelling photochemistry in alpine valleys

    NASA Astrophysics Data System (ADS)

    Brulfert, G.; Chemel, C.; Chaxel, E.; Chollet, J. P.

    2005-09-01

    Road traffic is a serious problem in the Chamonix Valley, France: traffic, noise and above all air pollution worry the inhabitants. The big fire in the Mont-Blanc tunnel made it possible, in the framework of the POVA project (POllution in Alpine Valleys), to undertake measurement campaigns with and without heavy-vehicle traffic through the Chamonix and Maurienne valleys, towards Italy (before and after the tunnel re-opening). Modelling is one of the aspects of POVA and should make it possible to explain the processes leading to episodes of atmospheric pollution, both in summer and in winter. Atmospheric prediction model ARPS 4.5.2 (Advanced Regional Prediction System), developed at the CAPS (Center for Analysis and Prediction of Storms) of the University of Oklahoma, enables to resolve the dynamics above a complex terrain. This model is coupled to the TAPOM 1.5.2 atmospheric chemistry (Transport and Air POllution Model) code developed at the Air and Soil Pollution Laboratory of the Ecole Polytechnique Fédérale de Lausanne. The numerical codes MM5 and CHIMERE are used to compute large scale boundary forcing.

    This paper focuses on modelling Chamonix valley using 300-m grid cells to calculate the dynamics and the reactive chemistry which makes possible to accurately represent the dynamics in the Chamonix valley (slope and valley winds) and to process chemistry at fine scale. The summer 2003 intensive campaign was used to validate the model and to study chemistry. NOy according to O3 reduction demonstrates a VOC controlled regime, different from the NOx controlled regime expected and observed in the nearby city of Grenoble.

  6. Lower Mississippian trilobites from southern New Mexico

    USGS Publications Warehouse

    Brezinski, D.K.

    2000-01-01

    Twenty-three species of trilobites are recognized in the lower Mississippian Caballero and Lake Valley Formations of southern New Mexico. Species exhibit a segregation into shelf and off-shelf faunas, and can be subdivided into three distinct stratigraphic faunas. Species found in the Caballero Formation are similar to those found in the Chouteau Formation of Missouri. A second fauna, comprising species found in the Alamogordo, Nunn, and Tierra Blanca Members of the Lake Valley Formation, is correlated with the Fern Glen and Burlington Formations of Missouri. The third fauna found in the Arcente and Dona Aha Members of the Lake Valley Formation is correlated with the Warsaw and Salem Formations of the United States midcontinent region. Named species from the Kinderhookian Caballero Formation include: Dixiphopyge armata (Vogdes, 1891), Comptonaspis swallowi (Shumard, 1855), Brachymetopus indianwellsensis new species, Ameropiltonia perplexa new species, Griffithidella caballeroensis new species, and Kollarcephalus granatai new genus and new species. Named species from the Lake Valley Formation include: Pudoproetus fernglenensis (Weller, 1909), Breviphillipsia semiteretis Hessler, 1963, Griffithidella doris (Hall 1860), Phillibole planucauda (Brezinski, 1998), Piltonia carlakertisae new species, Australosutura llanoensis Brezinski, 1998, Thigriffides triangulatus new species, Thigriffides? alamogordoensis new species, Namuropyge newmexicoensis new species, Nunnaspis stitti new genus and new species, Hesslerides arcentensis new genus and new species, as well as an unnamed species of Proetides Hessler, 1962, Namuropyge Brezinski, 1988, and Thigriffides Hessler, 1965.

  7. 27 CFR 9.191 - Ramona Valley.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... Ramona Valley viticultural area is located in central San Diego County, California. The area's boundaries..., passing through Barona Valley, to the peak (1,002 feet) near the center of the unnamed island in the San...

  8. Valley evolution by meandering rivers

    NASA Astrophysics Data System (ADS)

    Limaye, Ajay Brian Sanjay

    Fluvial systems form landscapes and sedimentary deposits with a rich hierarchy of structures that extend from grain- to valley scale. Large-scale pattern formation in fluvial systems is commonly attributed to forcing by external factors, including climate change, tectonic uplift, and sea-level change. Yet over geologic timescales, rivers may also develop large-scale erosional and depositional patterns that do not bear on environmental history. This dissertation uses a combination of numerical modeling and topographic analysis to identify and quantify patterns in river valleys that form as a consequence of river meandering alone, under constant external forcing. Chapter 2 identifies a numerical artifact in existing, grid-based models that represent the co-evolution of river channel migration and bank strength over geologic timescales. A new, vector-based technique for bank-material tracking is shown to improve predictions for the evolution of meander belts, floodplains, sedimentary deposits formed by aggrading channels, and bedrock river valleys, particularly when spatial contrasts in bank strength are strong. Chapters 3 and 4 apply this numerical technique to establishing valley topography formed by a vertically incising, meandering river subject to constant external forcing---which should serve as the null hypothesis for valley evolution. In Chapter 3, this scenario is shown to explain a variety of common bedrock river valley types and smaller-scale features within them---including entrenched channels, long-wavelength, arcuate scars in valley walls, and bedrock-cored river terraces. Chapter 4 describes the age and geometric statistics of river terraces formed by meandering with constant external forcing, and compares them to terraces in natural river valleys. The frequency of intrinsic terrace formation by meandering is shown to reflect a characteristic relief-generation timescale, and terrace length is identified as a key criterion for distinguishing these

  9. 77 FR 38793 - Grand Valley Rural Power Lines, Inc., Yampa Valley Electric Association, Inc., Intermountain...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-06-29

    ... Energy Regulatory Commission Grand Valley Rural Power Lines, Inc., Yampa Valley Electric Association, Inc., Intermountain Rural Electric Association, Tri-State Generation and Transmission Association, Inc. v. Public... CFR 385.206 and 385.212 (2011), Grand Valley Rural Power Lines, Inc., Yampa Valley...

  10. 27 CFR 9.57 - Green Valley of Russian River Valley.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2011-04-01 2011-04-01 false Green Valley of Russian... Areas § 9.57 Green Valley of Russian River Valley. (a) Name. The name of the viticultural area described in this section is “Green Valley of Russian River Valley”. For purposes of part 4 of this chapter...

  11. 27 CFR 9.57 - Green Valley of Russian River Valley.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2014-04-01 2014-04-01 false Green Valley of Russian... Areas § 9.57 Green Valley of Russian River Valley. (a) Name. The name of the viticultural area described in this section is “Green Valley of Russian River Valley”. For purposes of part 4 of this chapter...

  12. 27 CFR 9.57 - Green Valley of Russian River Valley.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2012-04-01 2012-04-01 false Green Valley of Russian... Areas § 9.57 Green Valley of Russian River Valley. (a) Name. The name of the viticultural area described in this section is “Green Valley of Russian River Valley”. For purposes of part 4 of this chapter...

  13. 27 CFR 9.57 - Green Valley of Russian River Valley.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2013-04-01 2013-04-01 false Green Valley of Russian... Areas § 9.57 Green Valley of Russian River Valley. (a) Name. The name of the viticultural area described in this section is “Green Valley of Russian River Valley”. For purposes of part 4 of this...

  14. 78 FR 30965 - AG Valley Railroad, LLC-Operation Exemption-Ag Valley Holdings, LLC

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-05-23

    ... Surface Transportation Board AG Valley Railroad, LLC--Operation Exemption--Ag Valley Holdings, LLC AG... Facility trackage (the Line), in Chicago, Ill., pursuant to an operating agreement with Ag Valley Holdings, LLC, (Ag Valley Holdings). AVRR states that there are no mileposts on the Line. Based on the map...

  15. Comparison of inversion models using AIRSAR data for Death Valley, California

    NASA Technical Reports Server (NTRS)

    Kierein-Young, Kathryn S.

    1993-01-01

    Polarimetric Airborne Synthetic Aperture Radar (AIRSAR) data were collected for the Geologic Remote Sensing Field Experiment (GRSFE) over Death Valley, California, USA, in September 1989. AIRSAR is a four-look, quid-polarizaiton, three frequency instrument. It collects measurements at C-band (5.66 cm), L-band (23.98 cm), and P-band (68.13 cm), and has a GIFOV of 10 meters and a swath width of 12 kilometers. Because the radar measures at three wavelengths, different scales of surface roughness are measured. Also, dielectric constants can be calculated from the data. The scene used in this study is in Death Valley, California and is located over Trail Canyon alluvial fan, the valley floor, and Artists Drive alluvial fan. The fans are very different in mineralogic makeup, size, and surface roughness. Trail Canyon fan is located on the west side of the valley at the base of the Panamint Range and is a large fan with older areas of desert pavement and younger active channels. The source for the material on southern part of the fan is mostly quartzites and there is an area of carbonate source on the northern part of the fan. Artists Drive fan is located at the base of the Black Mountains on the east side of the valley and is a smaller, young fan with its source mostly from volcanic rocks. The valley floor contains playa and salt deposits that range from smooth to Devil's Golf course type salt pinnacles.

  16. Summer deposition of sulfate and reactive nitrogen to two alpine valleys in the Canadian Rocky Mountains

    NASA Astrophysics Data System (ADS)

    Wasiuta, Vivian; Lafrenière, Melissa J.; Norman, Ann-Lise; Hastings, Meredith G.

    2015-01-01

    Summer deposition of sulfate and reactive nitrogen (mainly nitrate, and ammonium) to two alpine valleys in the Southern Canadian Rocky Mountains was investigated to constrain their major sources and evaluate physiographic influences on deposition. The effects of elevation, aspect, and air mass trajectory were evaluated using stable isotope composition (δ15N-NO3-, δ18O-NO3-, and δ34S-SO42-) and major ion concentrations for bulk precipitation. Deposition in the two valleys was related to synoptic scale weather conditions and the route the air mass followed, the location of major emission sources relative to the study site, and atmospheric residence time. Distinct differences in deposition at a relatively small scale between two opposing alpine valleys was mainly related to the orientation of the two valleys relative to the physiography of the Western Canadian Cordillera and the dominant pathways of air mass transport. Sulfate was found to be dominantly from distant sources, while NO3- was strongly enhanced by emissions from local to regional combustion. Local to regional pollutants were preferentially transported to the NNW facing Robertson Valley during NW-upslope synoptic conditions while precipitation in the SE facing Haig Valley was from relatively clean air with minimal influence from local and regional pollutants particularly at the highest elevation site.

  17. 27 CFR 9.154 - Chiles Valley.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2010-04-01 2010-04-01 false Chiles Valley. 9.154... Chiles Valley. (a) Name. The name of the viticultural area described in this section is “Chiles Valley.” (b) Approved maps. The appropriate maps for determining the boundary of the Chiles...

  18. 27 CFR 9.23 - Napa Valley.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2010-04-01 2010-04-01 false Napa Valley. 9.23 Section... THE TREASURY LIQUORS AMERICAN VITICULTURAL AREAS Approved American Viticultural Areas § 9.23 Napa Valley. (a) Name. The name of the viticultural area described in this section is “Napa Valley.”...

  19. Hydrology and simulation of ground-water flow in Juab Valley, Juab County, Utah.

    USGS Publications Warehouse

    Thiros, Susan A.; Stolp, Bernard J.; Hadley, Heidi K.; Steiger, Judy I.

    1996-01-01

    Plans to import water to Juab Valley, Utah, primarily for irrigation, are part of the Central Utah Project. A better understanding of the hydrology of the valley is needed to help manage the water resources and to develop conjunctive-use plans.The saturated unconsolidated basin-fill deposits form the ground-water system in Juab Valley. Recharge is by seepage from streams, unconsumed irrigation water, and distribution systems; infiltration of precipitation; and subsurface inflow from consolidated rocks that surround the valley. Discharge is by wells, springs, seeps, evapotranspiration, and subsurface outflow to consolidated rocks. Ground-water pumpage is used to supplement surface water for irrigation in most of the valley and has altered the direction of groundwater flow from that of pre-ground-water development time in areas near and in Nephi and Levan.Greater-than-average precipitation during 1980-87 corresponds with a rise in water levels measured in most wells in the valley and the highest water level measured in some wells. Less-than average precipitation during 1988-91 corresponds with a decline in water levels measured during 1988-93 in most wells. Geochemical analyses indicate that the sources of dissolved ions in water sampled from the southern part of the valley are the Arapien Shale, evaporite deposits that occur in the unconsolidated basin-fill deposits, and possibly residual sea water that has undergone evaporation in unconsolidated basin-fill deposits in selected areas. Water discharging from a spring at Burriston Ponds is a mixture of about 70 percent ground water from a hypothesized flow path that extends downgradient from where Salt Creek enters Juab Valley and 30 percent from a hypothesized flow path from the base of the southern Wasatch Range.The ground-water system of Juab Valley was simulated by using the U.S. Geological Survey modular, three-dimensional, finite-difference, ground-water flow model. The numerical model was calibrated to simulate

  20. The gradational history of southern Ismenius Lacus

    NASA Technical Reports Server (NTRS)

    Grant, J. A.; Schultz, P. H.

    1991-01-01

    Two epochs of accelerated gradation affected the geomorphic evolution of southern Ismenius Lacus. These periods of enhanced gradational activity were likely related to periods of more clement climate induced by release of either recycled exogenic or juvenile endogenic atmospheric volatiles. Variations in the intensity and duration of gradation during the second epoch are indicated by the variability in the timing of cessation and degree of air fall deposit removal across the study area. Overall intensity of gradation decreased through successive epochs based on: (1) the decreasing diameter at which cumulative statistics from the respective surfaces cease to follow the expected production function; and (2) the decrease in size/increase in density of preserved valley networks incised into surfaces of differing age. A comparable decrease in valley density with time has been noted in the Isidis region.

  1. Birds of the St. Croix River valley: Minnesota and Wisconsin

    USGS Publications Warehouse

    Faanes, Craig A.

    1981-01-01

    The St. Croix River Valley encompasses nearly 11,550 km2 in east-central Minnesota and northwestern Wisconsin. A wide range of habitats are available for birds including upland oak, lowland deciduous, maple-basswood, lowland and upland coniferous forests, natural basin wetlands, and grasslands. Situated in the north-central region of the United States, the valley is a biological 'crossroads' for many species. Because of the mixed affinities of plant communities, the valley includes the northern and southern range limits for a number of species. Also, because the valley lies near the forest-prairie transition zone, many typical western breeding species (e.g. pintail, western meadowlark, yellow-headed blackbird) breed in proximity to typical eastern species such as tufted titmouse, eastern meadowlark, and cardinal. From 1966 to 1980, I conducted extensive surveys of avian distribution and abundance in the St. Croix River Valley. I have supplemented the results of these surveys with published and unpublished observations contributed by many ornithologists. These additional data include compilations from Christmas Bird Counts sponsored by the National Audubon Society and from the Breeding Bird Survey coordinated by the U.S. Fish and Wildlife Service. Three hundred fourteen species have been recorded in the study area; data are presented on the migration period, nesting season distribution, winter distribution, relative abundance, and habitat use of each species. Recognizing the uniqueness of the area, and its importance not only to wildlife but also to man, the U.S. Congress designated the St. Croix a National Scenic Riverway. This action provided a considerable degree of protection to lands along and directly adjacent to the river. Unfortunately, no similar legal measure exists to protect lands away from the river. With the exception of the northern quarter of the St. Croix River Valley, agricultural interests have made significant inroads into the habitat base. The

  2. Field Surveys, IOC Valleys. Volume III, Part I. Cultural Resources Survey, Dry Lake Valley, Nevada.

    DTIC Science & Technology

    1981-08-01

    use of the valley has been limited to livestock grazing. b. Geology and Soils : This discussion of the geologic charac- teristics of Dry Lake Valley...aged alluvial fans are the predominant surficial geologic units within the valley. Soils range from.sandy gravels near the mountain fronts to sandy silts...Coyote Wash, the central stream channel flowing into Dry Lake Valley from Muleshoe Valley, contains with fine-grained soils and is grown over with

  3. Soil formation in the Tsauchab Valley, Namibia

    NASA Astrophysics Data System (ADS)

    Eden, Marie; Bens, Oliver; Ramisch, Arne; Schwindt, Daniel; Völkel, Jörg

    2016-04-01

    The BMBF-funded project GeoArchives (Spaces) investigates soils and sediments in Southern Africa. A focus area lies on the Tsauchab Valley (Namibia), South of the Naukluft mountain range (24°26'40'' S, 16°10'40'' E). On a gently sloping alluvial fan facing East towards the river, the surface is characterized by a desert pavement covering soils used as farmland. The landscape units were mapped and the area at the lower slope of a hill was divided into three units: a rinsing surface and a gravel plain, separated by a channel. On these surfaces soil profiles were excavated. Profile description followed the German system (Bodenkundliche Kartieranleitung KA 5) and disturbed samples were taken at various depths and analysed in the lab. Undisturbed soil cores with a volume of 100 cm³ were taken just below the surface at a depth of ~1-6 cm. Lab analyses included texture and gravel content, colour, pH, electrical conductivity, carbonates, CNS, cation exchange capacity, pedogenic oxides, main and trace elements (XRF), and clay mineral distribution (XRD). Undisturbed samples were used to determine soil water retention curve, air permeability and bulk density. The profiles revealed moderately developed cambic soils rich in clay minerals and with total carbon contents ranging up to 1.8 %, bearing shrubs and after episodic rainfall a dense grass vegetation. Their genesis is discussed and interpreted in the context of the landscape and climate history of this semi-desert environment.

  4. Late Quaternary environments in Ruby Valley, Nevada

    USGS Publications Warehouse

    Thompson, R.S.

    1992-01-01

    Palynological data from sediment cores from the Ruby Marshes provide a record of environmental and climatic changes over the last 40,000 yr. The modern marsh waters are fresh, but no deeper than ???3 m. A shallow saline lake occupied this basin during the middle Wisconsin, followed by fresh and perhaps deep waters by 18,000 to 15,000 yr B.P. No sediments were recovered for the period between 15,000 and 11,000 yr B.P., possibly due to lake desiccation. By 10,800 yr B.P. a fresh-water lake was again present, and deeper-than-modern conditions lasted until 6800 yr B.P. The middle Holocene was characterized by very shallow water, and perhaps complete desiccation. The marsh system deepened after 4700 yr B.P., and fresh-water conditions persisted until modern times. Vegetation changes in Ruby Valley were more gradual than those seen in the paleolimno-logical record. Sagebrush steppe was more widespread than at present through the late Pleistocene and early Holocene, giving way somewhat to expanded shadscale vegetation between 8500 and 6800 yr B.P. Shadscale steppe contracted by 4000 yr B.P., but had greater than modern coverage until 1000 to 500 yr ago. Pinyon-juniper woodland was established in the southern Ruby Mountains by 4700 yr B.P. ?? 1992.

  5. Magnetotelluric Data, San Luis Valley, Colorado

    USGS Publications Warehouse

    Rodriguez, Brian D.; Williams, Jackie M.

    2008-01-01

    The San Luis Valley region population is growing. Water shortfalls could have serious consequences. Future growth and land management in the region depend on accurate assessment and protection of the region?s ground-water resources. An important issue in managing the ground-water resources is a better understanding of the hydrogeology of the Santa Fe Group and the nature of the sedimentary deposits that fill the Rio Grande rift, which contain the principal ground-water aquifers. The shallow unconfined aquifer and the deeper confined Santa Fe Group aquifer in the San Luis Basin are the main sources of municipal water for the region. The U.S. Geological Survey (USGS) is conducting a series of multidisciplinary studies of the San Luis Basin located in southern Colorado. Detailed geologic mapping, high-resolution airborne magnetic surveys, gravity surveys, an electromagnetic survey (called magnetotellurics, or MT), and hydrologic and lithologic data are being used to better understand the aquifers. The MT survey primary goal is to map changes in electrical resistivity with depth that are related to differences in rock types. These various rock types help control the properties of aquifers. This report does not include any data interpretation. Its purpose is to release the MT data acquired at 24 stations. Two of the stations were collected near Santa Fe, New Mexico, near deep wildcat wells. Well logs from those wells will help tie future interpretations of this data with geologic units from the Santa Fe Group sediments to Precambrian basement.

  6. McMurdo Dry Valleys

    NASA Technical Reports Server (NTRS)

    2002-01-01

    One of the few areas of Antarctica not covered by thousands of meters of ice, the McMurdo Dry Valleys stand out in this satellite image. For a few weeks each summer temperatures are warm enough to melt glacial ice, creating streams that feed freshwater lakes that lie at the bottom of the valleys. Beneath a cap of ice these lakes remains unfrozen year-round, supporting colonies of bacteria and phytoplankton. Over the past 14 years, however, summers have been colder than usual, and the lakes are becoming more and more frozen. If the trend continues, the biological communities they support may go into hibernation. Most of Antarctica has cooled along with the Dry Valleys, in contrast to much of the rest of the Earth, which has warmed over the past 100 years. No one knows if the trend is related to global climate, or just a quirk in the weather. This image was acquired by Landsat 7's Enhanced Thematic Mapper plus (ETM+) instrument on December 18, 1999. For more information, visit: National Public Radio's Mixed Signals from Antarctica Declassified Satellite Imagery of the McMurdo Dry Valleys Image by Robert Simmon, based on data provided by the NASA GSFC Oceans and Ice Branch and the Landsat 7 Science Team

  7. Diablo Valley College Trends, 1992.

    ERIC Educational Resources Information Center

    Birdsall, Les; And Others

    This report provides 31 charts showing trends in enrollment; transfer students; and ethnic and gender characteristics of students, faculty, and staff at Diablo Valley College (DVC), in California, up to fall 1992. Following a brief introduction highlighting statewide trends, charts are provided for the following areas: (1) DVC fall enrollments…

  8. Navigating the valley of death

    NASA Astrophysics Data System (ADS)

    Dacey, James

    2014-11-01

    Taking an innovation from the lab to the market is hard in any discipline, but physics start-ups face some unique challenges crossing the so-called "valley of death". James Dacey speaks to scientists and business professionals in the Boston area of the US who have dared to take on this journey.

  9. Small Glaciofluvial Valleys on Amazonian Mars

    NASA Astrophysics Data System (ADS)

    Fassett, C.; Dickson, J.; Head, J. W.; Levy, J. S.; Marchant, D. R.

    2009-12-01

    We present new observations of small valleys associated with glacial features in the Martian mid-latitudes, based on a survey of images from the Context Camera (CTX) on the Mars Reconnaissance Orbiter. These valleys are small (~50-400 m wide) and short (<~10 km in length); indeed, the small-scale of these valleys appears to have hindered earlier recognition. The valleys usually are adjacent to probable glacial landforms (lobate debris aprons, lineated valley fill, concentric crater fill and viscous flow features); the mechanism most likely to explain their origin is top-down melting of these cold-based glaciers. Some valleys have associated sedimentary deposits (small fans) (e.g., Fig. 1). Both stratigraphic relations and crater counting constrain most such valleys to the Amazonian period. The observed glaciofluvial valleys are typically on slopes of <<10°, which makes them morphologically distinct from young Mars gullies, which form only on steep slopes (~15-30°). These features are also qualitatively different from valley networks that date from the Noachian/Early Hesperian, as these larger valley systems were integrated into networks that were up to hundreds or thousands of kilometers in extent. Thus, we interpret these small glaciofluvial valleys as representing a distinct class of fluvial features on Mars. Their presence shows that the hydrology of Amazonian Mars is more diverse than previously thought. Figure 1. A small valley emanating from concentric crater fill (interpreted as glacial / ice-rich) inside a 70-km crater (352.5°E, 41.5°S; CTX image P16_007256_1383). The valley begins in a small alcove, where remnant glacial materials are now ~1 km from the valley head. The valley is ~5.5 km long, has an average slope of 5°, and terminates in an elongate fan.

  10. Impacts from valley fill design and age on water quality in mountaintop mined watersheds

    NASA Astrophysics Data System (ADS)

    Ross, M. R.; Lindberg, T. T.; Voss, K.; Bernhardt, E. S.

    2012-12-01

    Mountaintop mining (MTM) for coal is the strongest driver of landscape disturbance throughout central Appalachia. The MTM process removes mountain ridges and deposits the resulting spoil into adjacent valleys. Recent research has shown that streams receiving waters from these valley fills exhibit consistent increases in the concentrations of base cations (Ca2+, Mg2+), metals, and anions (HCO3-SO42-) that correlate strongly with an increase in conductivity. Together, these chemical changes degrade the aquatic ecosystems downstream of valley fills and impair the ecosystem services they provide by extirpating sensitive macro-invertebrate taxa and toxicity to fish. Nearly 50% of the variability in conductivity and individual ion species concentration can be explained simply by the positive correlation between percent of catchment area mined and solute concentration. Yet, there is a wide range of valley fill size (0.25-225 hectares), age (1-40 years old), and design (from completely re-contoured landscapes to untouched, dumped spoil material) which may further explain observed patterns in water quality and biogeochemistry in MTM-impacted streams. For this study we asked the question: Do fill construction techniques and fill age predict patterns of stream water quality as measured by ion and metal concentration? To answer this question, we used a synoptic dataset collected from 30 valley fills in the Hobet mining complex in southern West Virginia and a comprehensive dataset collected by the West Virginia Department of Environmental Protection. We show that conductivity and ion concentrations are predicted better by valley fill size (p value < 0.05 ) than by valley fill age (statistically insignificant). These results suggest that impacts from MTM on aquatic ecosystems and the ecosystem services they provide may last over long time scales (>50 years), and that trends of expanding valley fill size over the 2000's may have disproportionately negative impacts on the streams

  11. Topological spin and valley pumping in silicene

    PubMed Central

    Luo, Wei; Sheng, L.; Wang, B. G.; Xing, D. Y.

    2016-01-01

    We propose to realize adiabatic topological spin and valley pumping by using silicene, subject to the modulation of an in-plane ac electric field with amplitude Ey and a vertical electric field consisting of an electrostatic component and an ac component with amplitudes and . By tuning and , topological valley pumping or spin-valley pumping can be achieved. The low-noise valley and spin currents generated can be useful in valleytronic and spintronic applications. Our work also demonstrates that bulk topological spin or valley pumping is a general characteristic effect of two-dimensional topological insulators, irrelevant to the edge state physics. PMID:27507592

  12. Spirit's West Valley Panorama

    NASA Technical Reports Server (NTRS)

    2008-01-01

    NASA'S Mars Exploration Rover Spirit captured this westward view from atop a low plateau where Sprit spent the closing months of 2007.

    After several months near the base of the plateau called 'Home Plate' in the inner basin of the Columbia Hills range inside Gusev Crater, Spirit climbed onto the eastern edge of the plateau during the rover's 1,306th Martian day, or sol, (Sept. 5, 2007). It examined rocks and soils at several locations on the southern half of Home Plate during September and October. It was perched near the western edge of Home Plate when it used its panoramic camera (Pancam) to take the images used in this view on sols 1,366 through 1,369 (Nov. 6 through Nov. 9, 2007). With its daily solar-energy supply shrinking as Martian summer turned to fall, Spirit then drove to the northern edge of Home Plate for a favorable winter haven. The rover reached that northward-tilting site in December, in time for the fourth Earth-year anniversary of its landing on Mars. Spirit reached Mars on Jan. 4, 2004, Universal Time (Jan. 3, 2004, Pacific Standard Time). It landed at a site at about the center of the horizon in this image.

    This panorama covers a scene spanning left to right from southwest to northeast. The western edge of Home Plate is in the foreground, generally lighter in tone than the more distant parts of the scene. A rock-dotted hill in the middle distance across the left third of the image is 'Tsiolkovski Ridge,' about 30 meters or 100 feet from the edge of Home Plate and about that same distance across. A bump on the horizon above the left edge of Tsiolkovski Ridge is 'Grissom Hill,' about 8 kilometers or 5 miles away. At right, the highest point of the horizon is 'Husband Hill,' to the north and about 800 meters or half a mile away.

    This view combines separate images taken through Pancam filters centered on wavelengths of 753 nanometers, 535 nanometers and 432 nanometers to produce an approximately true-color panorama.

  13. New Zealand's Southern Alps

    NASA Technical Reports Server (NTRS)

    2001-01-01

    The rugged Southern Alps extend some 650 kilometers along the western side of New Zealand's South Island. The mountains are often obscured by clouds, which is probably why the Maoris called New Zealand 'Aotearoa', the long white cloud. The higher peaks are snow-covered all year round. Westerly winds bring clouds that drop over 500 centimeters of rain annually on luxuriant rain forest along the west coast. The drier eastern seaboard is home to the majority of the island's population.

    This pair of MISR images is from April 13, 2000 (Terra orbit 1712). The upper image is a natural color view from the instrument's vertical-viewing (nadir) camera. It is presented at a resolution of 550 meters per pixel. The lower image is a stereo anaglyph generated from the instrument's 46-degree and 26-degree forward-viewing cameras, and is presented at 275-meter per pixel resolution to show the portion of the image containing the Southern Alps in greater detail. Viewing the anaglyph in 3-D requires the use of red/blue glasses with the red filter over your left eye. To facilitate stereoscopic viewing, both images have been oriented with north at the left.

    The tallest mountain in the Southern Alps is Mt. Cook, at an elevation of 3754 meters. Its snow-covered peak is visible to the left of center in each of these MISR images. From the high peaks, glaciers have gouged long, slender mountain lakes and coastal fiords. Immediately to the southeast of Mt. Cook (to the right in these images), the glacial pale-blue water of Lake Pukaki stands out. Further to the south in adjacent valleys you can easily see Lakes Hawea and Wanaka, between which (though not visible here) is the Haast Pass Road, the most southerly of the few links between the east and west coast road systems. Further to the south is the prominent 'S' shape of Lake Wakatipu, 83 kilometers long, on the northern shore of which is Queenstown, the principal resort town of the island. The remote and spectacular Fiordland National

  14. New Zealand's Southern Alps

    NASA Technical Reports Server (NTRS)

    2001-01-01

    The rugged Southern Alps extend some 650 kilometers along the western side of New Zealand's South Island. The mountains are often obscured by clouds, which is probably why the Maoris called New Zealand 'Aotearoa', the long white cloud. The higher peaks are snow-covered all year round. Westerly winds bring clouds that drop over 500 centimeters of rain annually on luxuriant rain forest along the west coast. The drier eastern seaboard is home to the majority of the island's population.

    This pair of MISR images is from April 13, 2000 (Terra orbit 1712). The upper image is a natural color view from the instrument's vertical-viewing (nadir) camera. It is presented at a resolution of 550 meters per pixel. The lower image is a stereo anaglyph generated from the instrument's 46-degree and 26-degree forward-viewing cameras, and is presented at 275-meter per pixel resolution to show the portion of the image containing the Southern Alps in greater detail. Viewing the anaglyph in 3-D requires the use of red/blue glasses with the red filter over your left eye. To facilitate stereoscopic viewing, both images have been oriented with north at the left.

    The tallest mountain in the Southern Alps is Mt. Cook, at an elevation of 3754 meters. Its snow-covered peak is visible to the left of center in each of these MISR images. From the high peaks, glaciers have gouged long, slender mountain lakes and coastal fiords. Immediately to the southeast of Mt. Cook (to the right in these images), the glacial pale-blue water of Lake Pukaki stands out. Further to the south in adjacent valleys you can easily see Lakes Hawea and Wanaka, between which (though not visible here) is the Haast Pass Road, the most southerly of the few links between the east and west coast road systems. Further to the south is the prominent 'S' shape of Lake Wakatipu, 83 kilometers long, on the northern shore of which is Queenstown, the principal resort town of the island. The remote and spectacular Fiordland National

  15. Climate change and agricultural transformation in the Oaxaca Valley, Mexico

    SciTech Connect

    Dilley, F.B.

    1993-01-01

    The Valley of Oaxaca, a semi-arid region in the central highlands of southern Mexico, provides a case study through which to develop a methodology for climate change impact assessment. The causes and impacts of climate change originate in dialectic processes within a nexus of inter-dependent social, technical, environmental, cultural and academic production relations. Agriculture is the most important economic activity in the Valley, and rain-fed maize the most important crop. Harvest failures from droughts occur one year in four. Annual rainfall varies with large-scale convection of water vapor transported from the Pacific and Gulf of Mexico during summer, upper-air disturbances caused by hurricanes and El Ninos. Variations in maize yields and losses have roughly moisture availability during August. Yields and losses can be predicted using precipitation during this time, or directly from atmospheric circulation. Contemporary agriculture in the Valley of Oaxaca has both traditional and modern sectors, of which both may appear within individual communities and households. The traditional sector consists of semi-autonomous rural communities using traditional technology for subsistence farming. The modern sector uses tractors, irrigation pumps, agricultural chemicals and hybrid seeds to produce cash crops and dairy products. The evidence for climate change in the Valley is ambiguous and contradictory. Under wet or dry scenarios, climate change affects the rate and pathway of the absorption of Oaxaca's traditional rural communities into the wage labor market of the larger capitalist system. Increased moisture availability would raise land productivity, promoting cash cropping and development of the modern market-oriented agricultural sector and leading to land consolidation and rural-to-urban migration. Decreased moisture availability would inhibit cash-cropping but also lead to rural-to-urban migration due to decreased land productivity.

  16. Individualized Learning through Computerized Modular Scheduling, Second Report of Scheduling Project at Virgin Valley High School, Mesquite, Nevada.

    ERIC Educational Resources Information Center

    Allan, Blaine W.

    In 1963 Stanford University selected Virgin Valley High School in southern Nevada as one of four pilot schools to use computerized modular scheduling. Schedules for 165 students and assignments for 14 teachers were developed at the Stanford University Computer Computation Center using 30-minute modules with a total of 80 modules per week. After…

  17. Global positioning system surveying to monitor land subsidence in Sacramento Valley, California, USA

    USGS Publications Warehouse

    Ikehara, M.E.

    1994-01-01

    A subsidence research program began in 1985 to document the extent and magnitude of land subsidence in Sacramento Valley, California, an area of about 15 600 km2m, using Global Positioning System (GPS) surveying. In addition to periodic conventional spirit levelling, an examination was made of the changes in GPS-derived ellipsoidal height differences (summary differences) between pairs of adjacent bench marks in central Sacramento Valley from 1986 to 1989. The average rates of land subsidence in the southern Sacramento Valley for the past several decades were determined by comparing GPS-derived orthometric heights with historic published elevations. A maximum average rate of 0.053 m year-1 (0.90 m in 17 years) of subsidence has been measured. -Author

  18. Sediments, geomorphology, magnetostratigraphy, and vertebrate paleontology in the San Pedro Valley, Arizona

    SciTech Connect

    Lindsay, E.H.; Smith, G.A.; Haynes, C.V.; Opdyke, N.D. )

    1990-07-01

    The San Pedro Valley in southern Arizona was probably formed by block faulting during the Miocene. Sediments that filled the valley, primarily the St. David Formation, have yielded a robust vertebrate fossil record, calibrated during the last 25 years by magnetostratigraphy and isotopic dating of volcanic ejecta. This chronologic framework is combined with new sedimentologic, paleomagnetic, and geomorphic data to evaluate the influence of subsequent tectonism within the basin. The authors conclude that tectonism in the San Pedro Valley has been relatively quiescent following the initial block faulting and suggest that ensuring rates of sedimentation and incision were most likely controlled by climatic factors rather than tectonic-geologic ones. Vertebrate datum planes established in 1975 are revised on the basis of new paleontologic and geologic-isotopic data. The authors now recognize only three faunal datum planes in the St. David Formation, and have abandoned the youngest (Lepus) datum plane.

  19. Airborne electromagnetic and magnetic survey data of the Paradox and San Luis Valleys, Colorado

    USGS Publications Warehouse

    Ball, Lyndsay B.; Bloss, Benjamin R.; Bedrosian, Paul A.; Grauch, V.J.S.; Smith, Bruce D.

    2015-01-01

    In October 2011, the U.S. Geological Survey (USGS) contracted airborne magnetic and electromagnetic surveys of the Paradox and San Luis Valleys in southern Colorado, United States. These airborne geophysical surveys provide high-resolution and spatially comprehensive datasets characterizing the resistivity structure of the shallow subsurface of each survey region, accompanied by magnetic-field information over matching areas. These data were collected to provide insight into the distribution of groundwater brine in the Paradox Valley, the extent of clay aquitards in the San Luis Valley, and to improve our understanding of the geologic framework for both regions. This report describes these contracted surveys and releases digital data supplied under contract to the USGS.

  20. Early Permian conodont fauna and stratigraphy of the Garden Valley Formation, Eureka County, Nevada

    USGS Publications Warehouse

    Wardlaw, Bruce R.; Gallegos, Dora M.; Chernykh, Valery V.; Snyder, Walter S.

    2015-01-01

    The lower part of the Garden Valley Formation yields two distinct conodont faunas. One of late Asselian age dominated by Mesogondolella and Streptognathodus and one of Artinskian age dominated by Sweetognathus with Mesogondolella. The Asselian fauna contains the same species as those found in the type area of the Asselian in the southern Urals including Mesogondolella dentiseparata, described for the first time outside of the Urals. Apparatuses for Sweetognathus whitei, Diplognathodus stevensi, and Idioprioniodus sp. are described. The Garden Valley Formation represents a marine pro-delta basin and platform, and marine and shore fan delta complex deposition. The fan-delta complex was most likely deposited from late Artinskian to late Wordian. The Garden Valley Formation records tremendous swings in depositional setting from shallow-water to basin to shore.

  1. Early Permian conodont fauna and stratigraphy of the Garden Valley Formation, Eureka County, Nevada

    USGS Publications Warehouse

    Wardlaw, Bruce R.; Gallegos, Dora M.; Chernykh, Valery V.; Snyder, Walter S.

    2015-01-01

    The lower Part of the Garden Valley Formation yields two distinct conodont faunas. One of late Asselian age dominated by Mesogondolella and Streptognathodus and one of Artinskian age dominated by Sweetognathus with Mesogondolella. The Asselian fauna contains the same species as those found in the type area of the Asselian in the southern Urals including Mesogondolella dentiseparata, described for the first time outside of the Urals. Apparatuses for Sweetognathus whitei, Diplognathodus stevensi, and Idioprioniodus sp. are described. The Garden Valley Formation represents a marine pro-delta basin and platform, and marine and shore fan delta complex deposition. The fan-delta complex was most likely deposited from late Artinskian to lateWordian. The Garden Valley Formation records tremendous swings in depositional setting from shallow-water to basin to shore.

  2. Morphology of large valleys on Hawaii - Evidence for groundwater sapping and comparisons with Martian valleys

    NASA Technical Reports Server (NTRS)

    Kochel, R. Craig; Piper, Jonathan F.

    1986-01-01

    Morphometric data on the runoff and sapping valleys on the slopes of Hawaii and Molokai in Hawaii are analyzed. The analysis reveals a clear distinction between the runoff valleys and sapping valleys. The Hawaiian sapping valleys are characterized by: (1) steep valley walls and flat floors, (2) amphitheater heads, (3) low drainage density, (4) paucity of downstream tributaries, (5) low frequency of up-dip tributaries, and (6) structural and stratigraphic control on valley patterns. The characteristics of the Hawaiian sapping valleys are compared to Martian valleys and experimental systems, and good correlation between the data is detected. Flume experiments were also conducted to study the evolution of sapping valleys in response to variable structure and stratigraphy.

  3. Morphology of large valleys on Hawaii - Evidence for groundwater sapping and comparisons with Martian valleys

    NASA Technical Reports Server (NTRS)

    Kochel, R. Craig; Piper, Jonathan F.

    1986-01-01

    Morphometric data on the runoff and sapping valleys on the slopes of Hawaii and Molokai in Hawaii are analyzed. The analysis reveals a clear distinction between the runoff valleys and sapping valleys. The Hawaiian sapping valleys are characterized by: (1) steep valley walls and flat floors, (2) amphitheater heads, (3) low drainage density, (4) paucity of downstream tributaries, (5) low frequency of up-dip tributaries, and (6) structural and stratigraphic control on valley patterns. The characteristics of the Hawaiian sapping valleys are compared to Martian valleys and experimental systems, and good correlation between the data is detected. Flume experiments were also conducted to study the evolution of sapping valleys in response to variable structure and stratigraphy.

  4. An observational study of the summer Mediterranean Sea breeze front penetration into the complex topography of the Jordan Rift Valley

    NASA Astrophysics Data System (ADS)

    Naor, R.; Potchter, O.; Shafir, H.; Alpert, P.

    2017-01-01

    The Mediterranean summer sea breeze front (SBF) climatic features of penetration into the complex topography of the Jordan Rift Valley (JRV) were investigated. It was shown that the SBF penetration into the JRV occurs in a well-defined chronological order from north to south. One exception to this general rule is the breeze penetration of Sdom, which occurs after it has penetrated the Arava which is located further south, probably due to the micro-climatic effect of the Dead Sea. It was also noted that the breeze increases the local specific humidity as it reaches the JRV in spite of significant temperature increases. The temperature reaches its daily peak 2 to 3 h later in the southern valley compared to the northern valley and is suggested to be due to the later SBF penetration and the valley structure. The pre-SBF line features in the JRV are described.

  5. Impact of climate and parent material on chemical weathering in Loess-derived soils of the Mississippi River valley

    USGS Publications Warehouse

    Muhs, D.R.; Bettis, E. Arthur; Been, J.; McGeehin, J.P.

    2001-01-01

    Peoria Loess-derived soils on uplands east of the Mississippi River valley were studied from Louisiana to Iowa, along a south-to-north gradient of decreasing precipitation and temperature. Major element analyses of deep loess in Mississippi and Illinois show that the composition of the parent material is similar in the northern and southern parts of the valley. We hypothesized that in the warmer, wetter parts of the transect, mineral weathering should be greater than in the cooler, drier parts of the transect. Profile average values of CaO/TiO2, MgO/ TiO2, K2O/TiO2, and Na2O/TiO2, Sr/Zr, Ba/Zr, and Rb/Zr represent proxies for depletion of loess minerals such as calcite, dolomite, hornblende, mica, and plagioclase. All ratios show increases from south to north, supporting the hypothesis of greater chemical weathering in the southern part of the valley. An unexpected result is that profile average values of Al2O3/TiO2 and Fe2O3/TiO2 (proxies for the relative abundance of clay minerals) show increases from south to north. This finding, while contrary to the evidence of greater chemical weathering in the southern part of the transect, is consistent with an earlier study which showed higher clay contents in Bt horizons of loess-derived soils in the northern part of the transect. We hypothesize that soils in the northern part of the valley received fine-grained loess from sources to the west of the Mississippi River valley either late in the last glacial period, during the Holocene or both. In contrast, soils in the southern part of the valley were unaffected by such additions.

  6. Southern California landslides-an overview

    USGS Publications Warehouse

    ,

    2005-01-01

    Southern California lies astride a major tectonic plate boundary defined by the San Andreas Fault and numerous related faults that are spread across a broad region. This dynamic tectonic environment has created a spectacular landscape of rugged mountains and steep-walled valleys that compose much of the region’s scenic beauty. Unfortunately, this extraordinary landscape also presents serious geologic hazards. Just as tectonic forces are steadily pushing the landscape upward, gravity is relentlessly tugging it downward. When gravity prevails, landslides can occur.

  7. Radionuclide transport from yucca Mountain and Inter-basin Flow in Death Valley

    SciTech Connect

    Bredehoeft, J.; Fridrich, C.; King, C.HG.M.

    2007-07-01

    Hydrodynamics and the U.S. Geological survey conducted studies to evaluate far-field issues related to potential transport, by ground water, of radionuclide into Inyo County from Yucca Mountain, including Death Valley, and the evaluation of a connection between the Lower Carbonate Aquifer (LCA) and the biosphere. Our oversight and completed Cooperative Agreement research, and a number of other investigators research indicate that there is groundwater flow between the alluvial and carbonate aquifers both at Yucca Mountain and in Inyo County. The specific purpose of our research was to acquire geological, subsurface geology, and hydrologic data to: 1. Establish the existence of inter-basin flow between the Amargosa Basin and Death Valley Basin, 2. Characterize groundwater flow paths in the LCA through Southern Funeral Mountain Range, and 3. Evaluate the hydraulic connection between the Yucca Mountain repository and the major springs in Death Valley through the LCA. 4. Evaluate the hydraulic connection between the Yucca Mountain repository and Franklin Lake Playa. The hydraulic characterization of the LCA is of critical interest to Inyo County and the U.S. Department of Energy because: 1. The upward gradient in the LCA at Yucca Mountain provides a natural barrier to radionuclide transport, 2. The LCA is a necessary habitat resource for the endangered Devil's Hole pup fish, and 3. The LCA is the primary water supply and source of water to the major springs in Death Valley National Park. This paper presents the results of our study program to evaluate if inter-basin flow exists between the Amargosa and Death Valley Basins through the LCA. The study presents the results of our structural geology analysis of the Southern Funeral Mountain range, geochemical source analysis of spring waters in the region, and a numerical groundwater model to simulate inter-basin flow in the Southern Funeral Mountain range. (authors)

  8. Ground-Water Modeling of the Death Valley Region, Nevada and California

    USGS Publications Warehouse

    Belcher, W.R.; Faunt, C.C.; Sweetkind, D.S.; Blainey, J.B.; San Juan, C. A.; Laczniak, R.J.; Hill, M.C.

    2006-01-01

    The Death Valley regional ground-water flow system (DVRFS) of southern Nevada and eastern California covers an area of about 100,000 square kilometers and contains very complex geology and hydrology. Using a computer model to represent the complex system, the U.S. Geological Survey simulated ground-water flow in the Death Valley region for use with U.S. Department of Energy projects in southern Nevada. The model was created to help address contaminant cleanup activities associated with the underground nuclear testing conducted from 1951 to 1992 at the Nevada Test Site and to support the licensing process for the proposed geologic repository for high-level nuclear waste at Yucca Mountain, Nevada.

  9. Yellowstone and Long Valley - A Comparison of Two Restless Calderas

    NASA Astrophysics Data System (ADS)

    Hill, D. P.; Smith, R. B.

    2007-12-01

    Three large, silicic calderas in the conterminous United States have explosively erupted volumes > 300 km3 within in the last 2 million years -- Yellowstone caldera (Wyoming) Long Valley caldera (California) and the Vallez caldera (New Mexico) all located in extensional tectonic environments. All have shown varying levels of historic unrest. Pronounced unrest episodes at Yellowstone and Long Valley calderas over the past three decades stimulated extensive research on these two closely monitored calderas, and we explore some emerging similarities and differences. Yellowstone caldera is underlain by a long-lived (> 17 my) upper-mantle hot-spot that has fed a series of caldera-forming, extending to the southwest across southern Idaho to central Oregon including three caldera-forming eruptions from the Yellowstone caldera system in the last 2 my, the most recent at 600,000 ybp. It is marked by relatively low density and low seismic velocities extending to depths of at least 400 km and a regional topographic swell with elevations exceeding 2000 m. The extensive Yellowstone hydrothermal system has a thermal output of 5 GW. The most recent magmatic eruption dated at 70,000 ybp. By comparison, Long Valley caldera is underlain by a relatively modest "hot-spot", the locus of which appears to be influenced by a dilatational jog between the dextral Eastern California Shear Zone and the Walker Lane and westward delamination of the dense lithospheric root of the adjacent Sierra Nevada. The Long Valley system has fed multiple eruptions of over the past 4 my and a single caldera-forming eruption at 760,000 ybp. It is marked by a limited topographic swell but with the elevation of the caldera floor and adjacent basins comparable to the 2000-plus m elevation of the Yellowstone swell. Long Valley caldera hydrothermal system has a thermal output of 0.3 GW (including a 40 MW geothermal power plant). The most recent eruptions from the Long Valley Caldera- Mono Domes volcanic field

  10. Foehn Winds in the McMurdo Dry Valleys, Antarctica: A Driver of Environmental Change?

    NASA Astrophysics Data System (ADS)

    Speirs, J. C.; McGowan, H. A.

    2011-12-01

    Foehn winds are warm, dry and gusty winds that commonly occur in many mid-latitude mountainous regions. Detailed investigations into foehn winds in polar regions and their effects on landscape processes however, are rare. Foehn events are frequently experienced in the McMurdo Dry Valleys, Antarctica where they are caused by topographic modification of strong southwesterly airflow that is forced by synoptic-scale cyclones in the Amundsen/Ross Sea region. Recent research has shown that the intra and interannual frequency and intensity of foehn events varies in response to the position and frequency of these synoptic cyclones. The El Niño Southern Oscillation and the Southern Annular Mode are known sources of circulation anomalies in this region, and the frequency of foehn winds in the McMurdo Dry Valleys has been linked to these sources of climate variability. Despite the high frequency of foehn events in the McMurdo Dry Valleys, the influence of foehn winds on landscape processes of this polar desert is not well understood. Here we present research that integrates numerical weather model products, automatic weather station observations, stream discharge data and remote sensing techniques to quantify the influence of foehn winds on environmental processes in the McMurdo Dry Valleys. During summer, foehn winds play a critical role in raising air and soil temperatures above 0°C. Sublimation, meltwater generation and snow persistence are also shown to be significantly influenced by foehn winds and their affects on landscape processes which persist for several days after foehn wind cessation. Foehn winds play a large role in keeping the valleys snow and ice free. Any precipitation that does fall is quickly evaporated/sublimated by foehn winds. We conclude that foehn winds in the McMurdo Dry Valleys are the major cause of contemporary landscape change and aridity.

  11. From incision to infill: What a Late Quaternary valley system records?

    NASA Astrophysics Data System (ADS)

    Maselli, V.; Asioli, A.; Trincardi, F.; Ceregato, A.; Rizzetto, F.; Taviani, M.

    2014-12-01

    Erosional sequence boundaries and incised valleys buried in modern continental shelves represent the response of alluvial and coastal systems to Quaternary sea level oscillations. The study of the processes leading to valley incision reveals, at both regional and global scales, the influence of tectonics and eustatism on the evolution of fluvial landforms in coastal plains, while the sedimentary infill of the valley may represents one of the best archives to investigate past environmental changes. Although the time registered in the stratigraphic record represents only a small portion of the geological history, informations about the processes governing the evolution of past landscapes can be quantified by looking to erosional surfaces, where much of the time is condensed. The Manfredonia Incised Valley (southern Adriatic Sea), is a very interesting case of valley as it formed during a single episode of incision related to the last glacial sea level fall and was completely filled during the post-glacial sea level rise. The inverse-funnel shape of the incision, and its confinement toward the mid-inner shelf reveal the impact of the step-wise sea level fall on preexisting coastal morphologies, in particular during the MIS5-4 and MIS3-2 transitions. The 45 m thick sedimentary succession filling the valley recorded the post-glacial sea level rise, as revealed by the upward transition from fluvial to shallow-marine deposits, and the impact of base level and high-frequency climate change on river to coastal systems. The upper 15 m of infill, in particular, consist of multiple bayhead delta progradations occurred synchronously to the formation of sapropel S1, and represent the very-shallow water equivalent of the cm-thick sapropel layers accumulated offshore in the deeper southern Adriatic basin.

  12. Use of sequence-bounding surfaces for correlation and mapping in nonmarine, Incised-Valley reservoirs

    SciTech Connect

    Leckie, D.A.; Vanbeselaere, N.

    1995-11-01

    One of the problems with the application of sequence stratigraphy to nonmarine sediments is the use of effective surfaces for correlations. This case study from the Mannville Group of southern Saskatchewan demonstrates how major, regional bounding surfaces can be identified and correlated to produce a suite of maps that can be used for exploration purposes. In southern Saskatchewan, Cretaceous Mannville sediments, termed the Pense, Cantuar, and Success (S2) formations, overlie Jurassic S1 and older deposits. The interval, which is up to 100 m thick, was deposited over 40 to 50 m.y. and is riddled with unconformities and weathered horizons. Detailed stratigraphic correlations using well logs are difficult, imprecise, and highly suspect unless corroborated by core control. Jurassic Success S1 sediment was deposited in a restricted shallow-marine environment. The S2 was deposited as a sheet of quartzose, braided fluvial sandstone that unconformably cuts into the S1. The overlying Cantuar Formation consists of dominantly lithic sandstone, siltstone, and shale overlying a basal quartzose unit. The base of the Cantuar Formation has a high local relief and in places has eroded long, wide valleys into the Success and older Jurassic strata. The valleys were hundreds of kilometers long and up to 74 in deep. Remnants of the Success sediment are preserved as isolated, buried cuestas on the margins of the valley walls. Cantuar sediments represent the infill of an extensive valley system that took millions of years to fill. The fill was from meandering streams with abundant paleosols, shallow lacustrine, and splay deposits. The top of the Cantuar Formation is represented by chert and quartzose sandstones deposited in a north-south-trending estuarine system with several tributaries. Several play types, which are dominantly stratigraphic, have been identified and are related to the valley incision, valley fill, and preserved erosional cuesta remnants.

  13. Southern Spots

    NASA Technical Reports Server (NTRS)

    2005-01-01

    [figure removed for brevity, see original site] Context image for PIA03092 Southern Spots

    This VIS image of the south polar region was collected during the summer season. The markings of the pole are very diverse and easy to see after the winter frost has been removed.

    Image information: VIS instrument. Latitude 79.7S, Longitude 56.6E. 17 meter/pixel resolution.

    Note: this THEMIS visual image has not been radiometrically nor geometrically calibrated for this preliminary release. An empirical correction has been performed to remove instrumental effects. A linear shift has been applied in the cross-track and down-track direction to approximate spacecraft and planetary motion. Fully calibrated and geometrically projected images will be released through the Planetary Data System in accordance with Project policies at a later time.

    NASA's Jet Propulsion Laboratory manages the 2001 Mars Odyssey mission for NASA's Office of Space Science, Washington, D.C. The Thermal Emission Imaging System (THEMIS) was developed by Arizona State University, Tempe, in collaboration with Raytheon Santa Barbara Remote Sensing. The THEMIS investigation is led by Dr. Philip Christensen at Arizona State University. Lockheed Martin Astronautics, Denver, is the prime contractor for the Odyssey project, and developed and built the orbiter. Mission operations are conducted jointly from Lockheed Martin and from JPL, a division of the California Institute of Technology in Pasadena.

  14. Southern Clouds

    NASA Technical Reports Server (NTRS)

    2005-01-01

    [figure removed for brevity, see original site] Context image for PIA03026 Southern Clouds

    This image shows a system of clouds just off the margin of the South Polar cap. Taken during the summer season, these clouds contain both water-ice and dust.

    Image information: VIS instrument. Latitude 80.2S, Longitude 57.6E. 17 meter/pixel resolution.

    Note: this THEMIS visual image has not been radiometrically nor geometrically calibrated for this preliminary release. An empirical correction has been performed to remove instrumental effects. A linear shift has been applied in the cross-track and down-track direction to approximate spacecraft and planetary motion. Fully calibrated and geometrically projected images will be released through the Planetary Data System in accordance with Project policies at a later time.

    NASA's Jet Propulsion Laboratory manages the 2001 Mars Odyssey mission for NASA's Office of Space Science, Washington, D.C. The Thermal Emission Imaging System (THEMIS) was developed by Arizona State University, Tempe, in collaboration with Raytheon Santa Barbara Remote Sensing. The THEMIS investigation is led by Dr. Philip Christensen at Arizona State University. Lockheed Martin Astronautics, Denver, is the prime contractor for the Odyssey project, and developed and built the orbiter. Mission operations are conducted jointly from Lockheed Martin and from JPL, a division of the California Institute of Technology in Pasadena.

  15. Late Cenozoic sedimentation in Pilot Knob Valley, California

    NASA Astrophysics Data System (ADS)

    Rittase, W. M.; Walker, J. D.; Kirby, E.; Andrew, J.; Wan, E.

    2012-12-01

    In Pilot Knob Valley (PKV), active inversion of a Pliocene-mid Pleistocene basin presents the opportunity to understand the spatial and temporal development of an enigmatic basin astride a major transform boundary in California. Here, a ~1000-m-thick package of exposed Late Cenozoic strata has been uplifted and tilted to the northeast. Based on new age and provenance data, we adopt the name Pilot Knob formation (PKfm) to describe much of these exposed rocks north of the Garlock fault (GF) and east of Christmas Canyon gate. Post-Miocene development of PKV is strongly influenced by the sinistral GF, the newly identified Marine Gate fault (MGF) and dextral Eastern California shear zone. The PKfm consists of three lithofacies members, from base to top: (1) rocks derived from Eagle Crags to the south; (2) Randsburg Wash lacustrine rocks; and (3) an upper member derived from the Slate Range. Tephrochronologic data from four PKfm ash samples brackets deposition of lacustrine Randsburg Wash Member rocks between 3.7-3.1 Ma and lacustrine rocks of the Slate Range Member between 1.2-0.6 Ma. A fifth tephrochronologic sample from lacustrine-distal alluvial sediments south of the GF near Christmas Canyon brackets deposition of a possible PKfm facies at ~3.1 Ma. A 3-stage tectonic model for northern PKV explains changing provenance patterns. Prior to ~3.1 Ma, the western PKV paleo-low lay north of the current GF adjacent to the southern Slate Range and connected to Searles Valley. The MGF cuts adjacent to the southern face of the Slate Range and southern Searles Valley with up to 7.5 km of sinistral oblique-normal slip between ~5-2.5 Ma. Eagle Crags fanglomerate deposition may continue after 3.7 Ma west of the Randsburg Wash-Searles Valley spillway, but these rocks have been eroded away. By ~3.7 Ma, northward progradation of Eagle Crags fanglomerate waned and lacustrine sediments were deposited north of the GF and east of the Randsburg Wash-Searles Valley spillway. At ~3.1 Ma

  16. The Cenozoic evolution of the San Joaquin Valley, California

    USGS Publications Warehouse

    Bartow, J. Alan

    1991-01-01

    The San Joaquin Valley, which is the southern part of the 700-km-long Great Valley of California, is an asymmetric structural trough that is filled with a prism of upper Mesozoic and Cenozoic sediments up to 9 km thick; these sediments rest on crystalline basement rocks of the southwestward-tilted Sierran block. The San Joaquin sedimentary basin is separated from the Sacramento basin to the north by the buried Stockton arch and associated Stockton fault. The buried Bakersfield arch near the south end of the valley separates the small Maricopa-Tejon subbasin at the south end of the San Joaquin basin from the remainder of the basin. Cenozoic strata in the San Joaquin basin thicken southeastward from about 800 m in the north to over 9,000 m in the south. The San Joaquin Valley can be subdivided into five regions on the basis of differing structural style. They are the northern Sierran block, the southern Sierran block, the northern Diablo homocline, the westside fold belt, and the combined Maricopa-Tejon subbasin and southmargin deformed belt. Considerable facies variation existed within the sedimentary basin, particularly in the Neogene when a thick section of marine sediment accumulated in the southern part of the basin, while a relatively thin and entirely nonmarine section was deposited in the northern part. The northern Sierran block, the stable east limb of the valley syncline between the Stockton fault and the San Joaquin River, is the least deformed region of the valley. Deformation consists mostly of a southwest tilt and only minor late Cenozoic normal faulting. The southern Sierran block, the stable east limb of the valley syncline between the San Joaquin River and the Bakersfield arch, is similar in style to the northern part of the block, but it has a higher degree of deformation. Miocene or older normal faults trend mostly north to northwest and have a net down-to-the-west displacement with individual offsets of as much as 600 m. The northern Diablo

  17. The Owens Valley solar array

    NASA Technical Reports Server (NTRS)

    Hurford, G. J.; Gary, D. E.

    1989-01-01

    Solar microwave emission contains essential information for the study of the coronal magnetic structure of active regions and of thermal and nonthermal flare electrons. To exploit this potential requires BOTH imaging and spectroscopy with sufficient resolution to resolve spatial and spectral features. The VLA provides excellent solar imaging (when in the C and D configurations) but inadequate spectral coverage. The existing Owens Valley system has excellent spectral coverage but imaging that is adequate only for very simple sources. The Owens Valley system is currently undergoing an expansion, which when completed in October 1990 will provide a SOLAR-DEDICATED 5 antenna array (10 baselines). By using frequency-synthesis, this will provide a significant imaging capability in addition to its current spectral coverage.

  18. Groundwater quality in the Bear Valley and Lake Arrowhead Watershed, California

    USGS Publications Warehouse

    Mathany, Timothy; Burton, Carmen; Fram, Miranda S.

    2017-06-20

    Groundwater provides more than 40 percent of California’s drinking water. To protect this vital resource, the State of California created the Groundwater Ambient Monitoring and Assessment (GAMA) Program. The Priority Basin Project of the GAMA Program provides a comprehensive assessment of the State’s groundwater quality and increases public access to groundwater-quality information. The Bear Valley and Lake Arrowhead Watershed study areas in southern California compose one of the study units being evaluated.

  19. VALDRIFT--A Valley Atmospheric Dispersion Model.

    NASA Astrophysics Data System (ADS)

    Allwine, K. Jerry; Bian, Xindi; Whiteman, C. David; Thistle, Harold W.

    1997-08-01

    VALDRIFT (valley drift) is a valley atmospheric transport, diffusion, and deposition model. The model is phenomenological-that is, the dominant meteorological processes governing the behavior of the valley atmosphere are formulated explicitly in the model, although in a highly parameterized fashion. The key meteorological processes treated are 1) nonsteady and nonhomogeneous along-valley winds and turbulent diffusivities, 2) convective boundary layer growth, 3) inversion descent, and 4) nocturnal temperature inversion breakup. The model is applicable under relatively cloud-free, undisturbed synoptic conditions in which the winds in the valley are predominantly along the valley's axis. The model is configured to operate through one diurnal cycle for a single narrow valley. The inputs required are the valley topographic characteristics, pollutant release rate as a function of time and space, wind speed and direction as functions of time measured at one height, lateral and vertical turbulent eddy diffusivities as functions of stability, and the valley temperature inversion characteristics at sunrise. The outputs are three-dimensional concentration fields and ground-level deposition fields as functions of time. The scientific foundations of VALDRIFT are given in this paper along with a brief discussion of the model inputs and outputs. Air concentrations estimated by VALDRIFT compare favorably with results from a tracer experiment conducted in a deep mountain valley.

  20. Mechanically and optically controlled graphene valley filter

    SciTech Connect

    Qi, Fenghua; Jin, Guojun

    2014-05-07

    We theoretically investigate the valley-dependent electronic transport through a graphene monolayer modulated simultaneously by a uniform uniaxial strain and linearly polarized light. Within the Floquet formalism, we calculate the transmission probabilities and conductances of the two valleys. It is found that valley polarization can appear only if the two modulations coexist. Under a proper stretching of the sample, the ratio of the light intensity and the light frequency squared is important. If this quantity is small, the electron transport is mainly contributed by the valley-symmetric central band and the conductance is valley unpolarized; but when this quantity is large, the valley-asymmetric sidebands also take part in the transport and the valley polarization of the conductance appears. Furthermore, the degree of the polarization can be tuned by the strain strength, light intensity, and light frequency. It is proposed that the detection of the valley polarization can be realized utilizing the valley beam splitting. Thus, a graphene monolayer can be used as a mechanically and optically controlled valley filter.

  1. Aedes albopictus breeding in southern Germany, 2014.

    PubMed

    Werner, Doreen; Kampen, Helge

    2015-03-01

    Larvae, pupae and eggs of the Asian tiger mosquito Aedes albopictus were found in Freiburg, southern Germany, after submission of an adult mosquito specimen from that area to the 'Mückenatlas', a German instrument of passive mosquito surveillance. While previously collected Ae. albopictus in Germany were trapped on, or close to, service stations on motorways, suggesting introduction by vehicles from southern Europe, these new specimens were out of flight distance from the motorway on the one hand and indicate local reproduction on the other. The findings call for a thorough active and passive surveillance in exposed geographic regions such as the relatively warm German Upper Rhine Valley to prevent Ae. albopictus from establishing.

  2. Surface Sediment Geochemistry in and around the Hudson Shelf Valley Offshore of New York

    NASA Astrophysics Data System (ADS)

    Mecray, E. L.; ten Brink, M. B.; Butman, B.; Denny, J.; Murray, R. W.

    2001-05-01

    The Hudson Shelf Valley, an ancient submerged portion of the Hudson River, extends across the continental shelf offshore of New York and New Jersey. Between 1959 and 1987, the area near the head of the valley was used for disposal of approximately 1.20 x 108 m3 of dredged material and sewage sludge. The distribution of metal concentrations and sediment characteristics were used to investigate the transport and fate of the sediments and their associated contaminants. Surface (0-2cm) sediments collected at 440 stations throughout the New York Bight between 1993 and 1998 were used to establish the regional distribution of pollutant metals, grain size, organic carbon, and Clostridium perfringens spores. Sediments in the New York Bight are generally sandy, however fine-grained sediments are found in the axis of the Valley. Statistical methods identified common sources and chemical mobility within groups of anthropogenic and naturally-occurring elements. High metal concentrations, fine-grained sediments, and higher organic carbon concentrations co-occur in depo-centers within the Valley. Normalization of the metal concentrations to these factors shows higher metal concentrations on the fine-grained particles in sandy areas of the Bight, particularly along the southern shore of Long Island. These distributions have implications for evaluating the impact of the mass distribution for contaminated metals in different habitats and areas. Decreasing concentrations of pollutants with time are observed, reflecting reduced contaminant loading in the upper region of the Valley; however, concentrations are still above natural background levels.

  3. Chlorine-36 tracing of salinity sources in the Dry Valleys of Victoria Land, Antarctica

    NASA Astrophysics Data System (ADS)

    Carlson, Catherine A.; Phillips, Fred M.; Elmore, David; Bentley, Harold W.

    1990-02-01

    Chlorine-36 was used to trace the origins of salts in six saline lakes in the Dry Valleys of Southern Victoria Land, Antarctica. Characteristic 36Cl signatures were estimated for the various potential chloride sources, which include atmospheric deposition, rock weathering, seawater, and deep ground water. 36Cl /Cl ratios were measured in natural waters and salts from the Dry Valleys. Dilute lake waters (Cl - < 100 mg/l) were found to have 36Cl /Cl ratios in the range 100 × 10 -15 to 1,700 × 10 -15, whereas saline waters (Cl - > 1000 mg/l) had ratios in the range 9 × 10 -15 to 40 × 10 -15. Simple mixing models were employed to quantify the relative contributions of the various chloride sources to Lake Vanda and Don Juan Pond. These results show that Lake Vanda has received its chloride from both deep ground water and the Onyx River. Don Juan Pond has received nearly all its chloride from deep ground water, probably ultimately from rock-water interaction. Deep ground water is the principal source of chloride to the lakes of Wright Valley. However, preliminary data suggest that marine-derived salts or relict sea water may be a significant source of chloride to the lakes of Taylor Valley, implying a possible recent marine invasion that did not affect Wright Valley.

  4. A neotectonic tour of the Death Valley fault zone, Inyo County

    SciTech Connect

    Wills, C.J.

    1989-09-01

    The Death Valley fault zone has recently been evaluated by the Division of Mines and Geology for zoning under the Alquist-Priolo Special Studies Zones Act of 1972. This act requires the State Geologist to zone for special studies those faults that are sufficiently active and well defined as to constitute a potential hazard to structures from surface faulting or fault creep. The Death Valley fault zone is part of a system of faults that extends over 180 miles (300 km) from Fish Lake Valley in Nevada to the Garlock fault. The northern part of this system, the Northern Death Valley-Furnace Creek fault zone, is an active right-lateral fault zone. The southern part of the system, the Death Valley fault zone, is a right-lateral oblique-slip fault between Furnace Creek and Shoreline Butte. From Shoreline Butte to the Garlock fault, it is a right-lateral strike-slip fault. Landforms along this fault indicate that it is the source of many earthquakes and that it has been active in Holocene time. The heights of the scarps and magnitude of the smallest right-lateral offsets (4 feet; 1.2 m) suggest that the most recent of these events was M 6.5 or larger. The freshness of the geomorphic features and the youth of the offset materials suggest that event occurred late in the Holocene, and that multiple Holocene earthquakes have occurred.

  5. Chlorine-36 tracing of salinity sources in the dry valleys of Victoria land, Antarctica

    SciTech Connect

    Carlson, C.A.; Phillips, F.M. ); Elmore, D. ); Bentley, H.W. )

    1990-02-01

    Chlorine-36 was used to trace the origins of salts in six saline lakes in the Dry Valleys of Southern Victoria Land, Antarctica. Characteristic {sup 36}Cl signatures were estimated for the various potential chloride sources, which include atmospheric deposition, rock weathering, seawater, and deep ground water. {sup 36}Cl/Cl ratios were measured in natural waters and salts from the Dry Valleys. Dilute lake waters (Cl{sup {minus}} < 100 mg/l) were found to have {sup 36}Cl/Cl ratios in the range 100 {times} 10{sup {minus}15} to 1,700 {times} 10{sup {minus}15}, whereas saline waters (Cl{sup {minus}} > 1000 mg/l) had ratios in the range 9 {times} 10{sup {minus}15} to 40 {times} 10{sup {minus}15}. Simple mixing models were employed to quantify the relative contributions of the various chloride sources to Lake Vanda and Don Juan Pond. These results show that Lake Vanda has received its chloride from both deep ground water and the Onyx River. Don Juan Pond has received nearly all its chloride from deep ground water, probably ultimately from rock-water interaction. Deep ground water is the principal sources of chloride to the lakes of Wright Valley. However, preliminary data suggest that marine-derived salts or relict sea water may be a significant sources of chloride to the lakes of Taylor Valley, implying a possible recent marine invasion that did not affect Wright Valley.

  6. Optical tuning of electronic valleys (Conference Presentation)

    NASA Astrophysics Data System (ADS)

    Sie, Edbert J.; Gedik, Nuh

    2017-02-01

    Monolayer transition-metal dichalcogenides such as MoS2 and WS2 are prime examples of atomically thin semiconducting crystals that exhibit remarkable electronic and optical properties. They have a pair of valleys that can serve as a new electronic degree of freedom, and these valleys obey optical selection rules with circularly polarized light. Here, we discuss how ultrafast laser pulses can be used to tune their energy levels in a controllable valley-selective manner. The energy tunability is extremely large, comparable to what would be obtained using a hundred Tesla of magnetic field. We will also show that such valley tunability can be performed while we effectively manipulate the valley selection rules. Finally, we will explore the prospect of using this technique through photoemission spectroscopy to create a new phase of matter called a valley Floquet topological insulator.

  7. Intensive early season adulticide applications decrease arbovirus transmission throughout the Coachella Valley, Riverside County, California.

    PubMed

    Lothrop, Hugh D; Lothrop, Branka B; Gomsi, Donald E; Reisen, William K

    2008-08-01

    In the Coachella Valley of California the seasonal onset of St. Louis encephalitis virus (SLEV), western equine encephalomyelitis virus (WEEV), and West Nile virus (WNV) has been detected consistently at the shoreline of the Salton Sea near the community of North Shore. The timing and intensity of initial amplification in the Culex tarsalis Coquillett/wild bird cycle at this focus seemed closely linked to the subsequent dispersal of virus to the rest of the Coachella Valley and perhaps southern California. In 2004, an attempt was made to interrupt the amplification and dispersal of WNV using ground ultra-low volume (ULV) applications of Pyrenone 25-5. Although these localized treatments were started 1 month after the initial detection in April, surveillance indicated no dispersal from this focus at this time. However, these treatments appeared to have little effect, and WNV eventually was detected throughout the valley, with seven human cases reported in the urbanized upper valley near Palm Springs. In 2005, the initial detection of WNV at North Shore at the end of May was followed rapidly by dispersal throughout the valley precluding efforts at containment. Evaluation of ground and aerial applications at North Shore during May and June 2005, respectively, indicated variable kill of sentinel mosquitoes (overall mortality: ground, 43%; air, 34%) and limited control of the target Cx. tarsalis population. In 2006, aerial ULV applications with the same chemical were begun immediately following the first detection of virus in mid-April, resulting in an apparent reduction of Cx. tarsalis abundance and delay of WNV activity in the rural lower valley and a marked decline in transmission by Culex quinquefasciatus Say populations in the densely populated upper northwestern valley with no human cases reported.

  8. Iron and nutrient content of wind-erodible sediment in the ephemeral river valleys of Namibia

    NASA Astrophysics Data System (ADS)

    Dansie, A. P.; Wiggs, G. F. S.; Thomas, D. S. G.

    2017-08-01

    Research concerning the global distribution of aeolian dust sources has principally focussed on salt/clay pan and desiccated lacustrine emission areas. In southern Africa such sources are identified as Etosha Pan in northern Namibia and Makgadikgadi Pans in northern Botswana. Dust emitting from ephemeral river valleys, however, has been largely overlooked. Rivers are known nutrient transport pathways and the flooding regimes of ephemeral river valleys frequently replenish stores of fine sediment which, on drying, can become susceptible to aeolian erosion. Such airborne sediment may be nutrient rich and thus be significant for the fertilisation of marine waters once deposited. This study investigates the dust source sediments from three ephemeral river valleys in Namibia in terms of their particle size distribution and their concentrations of bioavailable N, P and Fe. We compare the nutrient content of these sediments from the ephemeral river valleys to those collected from Etosha and Makgadikgadi Pans and consider their relative ocean fertilising potential. Our results show that the ephemeral river valleys contain fine grained sediment similar in physical character to Etosha and Makgadikgadi Pans yet they have up to 43 times greater concentrations of bioavailable iron and enriched N and P macronutrients that are each important for ocean fertilisation. The known dust-emitting river valleys of Namibia may therefore be contributing a greater fertilisation role in the adjacent marine system than previously considered, and not-yet investigated. Given this finding a re-assessment of the potential role of ephemeral river valleys in providing nutrient-rich sediment into the aeolian and marine systems in other dryland areas is necessary.

  9. Observations and numerical simulations of downslope flow separation at a valley inversion

    NASA Astrophysics Data System (ADS)

    Strauss, Lukas; Serafin, Stefano; Grubišić, Vanda

    2016-04-01

    Severe turbulence downwind of a mountain ridge is often associated with large-amplitude gravity waves that are excited as the air flows over the ridge. Mountain waves can exert an adverse pressure-gradient force on the boundary layer and make it detach from the ground, leading to the formation of atmospheric rotors. However, in a more complex topographic setting, with a second mountain ridge downstream of the first and a valley in between, thermally and dynamically forced processes in the valley (e.g., cold pools or along-valley flow channelling) may be equally important for flow separation. Observations supporting this idea were made during the Terrain-induced Rotor Experiment in Owens Valley (California, USA) in the nighttime hours of 16 April 2006. In that case, an inversion was present in the valley and resultant buoyancy forces appear to have contributed significantly to flow separation well above the valley floor. In an attempt to understand better the thermal and dynamic forces determining this case, numerical simulations with the Weather Research and Forecasting (WRF) Model are run in a nested-domain configuration. The innermost model domain exhibits a horizontal grid spacing of 400 m and a vertical spacing of ~25 m at the ground and spans the southern portion of the Sierra Nevada. The sensitivity of model results (e.g. the valley inversion strength) to the chosen boundary-layer parameterization (e.g., Bougeault-Lacarrère, Mellor-Yamada-Janjic, or Shin-Hong 'scale-aware' PBL schemes) is studied. In a next step, the evaluation of the terms in the momentum equations along the trajectories of separated air parcels will help elucidate the relative importance of pressure-gradient forces and buoyancy forces for flow separation.

  10. California's restless giant: the Long Valley Caldera

    USGS Publications Warehouse

    Hill, David P.; Bailey, Roy A.; Hendley, James W.; Stauffer, Peter H.; Marcaida, Mae

    2014-01-01

    Scientists have monitored geologic unrest in the Long Valley, California, area since 1980. In that year, following a swarm of strong earthquakes, they discovered that the central part of the Long Valley Caldera had begun actively rising. Unrest in the area persists today. The U.S. Geological Survey (USGS) continues to provide the public and civil authorities with current information on the volcanic hazard at Long Valley and is prepared to give timely warnings of any impending eruption.

  11. Hydrogeologic characteristics of the valley-fill aquifer in the Arkansas River valley, Pueblo County, Colorado

    USGS Publications Warehouse

    Nelson, Gregory A.; Hurr, R.T.; Moore, John E.

    1989-01-01

    The hydrogeology of the valley-fill aquifer of the Arkansas River valley in Pueblo County, Colorado is presented in a series of three maps. The map shows: (1) the altitude and configuration of the bedrock surface beneath the valley-fill material; (2) the altitude and configuration of the water table in the spring of 1966; and (3) the saturation thickness of the valley-fill aquifer in the spring of 1966. (USGS)

  12. Hydrogeologic characteristics of the valley-fill aquifer in the Arkansas River valley, Prowers County, Colorado

    USGS Publications Warehouse

    Nelson, Gregory A.; Hurr, R.T.; Moore, John E.

    1989-01-01

    The hydrogeology of the valley-fill aquifer of the Arkansas River valley in Prowers County, Colorado is presented in a series of three maps. The map shows: (1) the altitude and configuration of the bedrock surface beneath the valley-fill material; (2) the altitude and configuration of the water table in the spring of 1966; and (3) the saturation thickness of the valley-fill aquifer in the spring of 1966. (USGS)

  13. Hydrogeologic framework of the Santa Clara Valley, California

    USGS Publications Warehouse

    Hanson, Randall T.

    2015-01-01

    The hydrologic framework of the Santa Clara Valley in northern California was redefined on the basis of new data and a new hydrologic model. The regional groundwater flow systems can be subdivided into upper-aquifer and lower-aquifer systems that form a convergent flow system within a basin bounded by mountains and hills on three sides and discharge to pumping wells and the southern San Francisco Bay. Faults also control the flow of groundwater within the Santa Clara Valley and subdivide the aquifer system into three subregions.After decades of development and groundwater depletion that resulted in substantial land subsidence, Santa Clara Valley Water District (SCVWD) and the local water purveyors have refilled the basin through conservation and importation of water for direct use and artificial recharge. The natural flow system has been altered by extensive development with flow paths toward major well fields. Climate has not only affected the cycles of sedimentation during the glacial periods over the past million years, but interannual to interdecadal climate cycles also have affected the supply and demand components of the natural and anthropogenic inflows and outflows of water in the valley. Streamflow has been affected by development of the aquifer system and regulated flow from reservoirs, as well as conjunctive use of groundwater and surface water. Interaquifer flow through water-supply wells screened across multiple aquifers is an important component to the flow of groundwater and recapture of artificial recharge in the Santa Clara Valley. Wellbore flow and depth-dependent chemical and isotopic data indicate that flow into wells from multiple aquifers, as well as capture of artificial recharge by pumping of water-supply wells, predominantly is occurring in the upper 500 ft (152 m) of the aquifer system. Artificial recharge represents about one-half of the inflow of water into the valley for the period 1970–1999. Most subsidence is occurring below 250 ft